Common Core: 6th Grade Math : Expressions & Equations

Study concepts, example questions & explanations for Common Core: 6th Grade Math

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Example Questions

Example Question #391 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 34=45-x\)

 

Possible Answers:

\(\displaystyle 9\)

\(\displaystyle 11\)

\(\displaystyle 10\)

\(\displaystyle 13\)

\(\displaystyle 12\)

Correct answer:

\(\displaystyle 11\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 45-9=36\)

\(\displaystyle 45-10=35\)

\(\displaystyle {\color{Teal} 45-11=34}\)

\(\displaystyle 45-12=33\)

\(\displaystyle 45-13=32\)

Because we are looking for the number that when subtracted from \(\displaystyle 45\) equals \(\displaystyle 34\), our correct answer is \(\displaystyle 11\)

Example Question #392 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 26=83-x\)

 

Possible Answers:

\(\displaystyle 56\)

\(\displaystyle 55\)

\(\displaystyle 59\)

\(\displaystyle 57\)

\(\displaystyle 58\)

Correct answer:

\(\displaystyle 57\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 83-59=24\)

\(\displaystyle 83-58=25\)

\(\displaystyle {\color{Teal} 83-57=26}\)

\(\displaystyle 83-56=27\)

\(\displaystyle 83-55=28\)

Because we are looking for the number that when subtracted from \(\displaystyle 83\) equals \(\displaystyle 26\), our correct answer is \(\displaystyle 57\)

Example Question #393 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 29=65-x\)

 

Possible Answers:

\(\displaystyle 37\)

\(\displaystyle 35\)

\(\displaystyle 34\)

\(\displaystyle 38\)

\(\displaystyle 36\)

Correct answer:

\(\displaystyle 36\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 65-35=30\)

\(\displaystyle 65-34=31\)

\(\displaystyle {\color{Teal} 65-36=29}\)

\(\displaystyle 65-37=28\)

\(\displaystyle 65-38=27\)

Because we are looking for the number that when subtracted from \(\displaystyle 65\) equals \(\displaystyle 29\), our correct answer is \(\displaystyle 36\)

Example Question #394 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 48=99-x\)

 

Possible Answers:

\(\displaystyle 54\)

\(\displaystyle 52\)

\(\displaystyle 53\)

\(\displaystyle 55\)

\(\displaystyle 51\)

Correct answer:

\(\displaystyle 51\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 99-52=47\)

\(\displaystyle 99-53=46\)

\(\displaystyle {\color{Teal} 99-51=48}\)

\(\displaystyle 99-54=45\)

\(\displaystyle 99-55=44\)

Because we are looking for the number that when subtracted from \(\displaystyle 99\) equals \(\displaystyle 48\), our correct answer is \(\displaystyle 51\)

Example Question #395 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

 \(\displaystyle 53=85-x\)

 

Possible Answers:

\(\displaystyle 26\)

\(\displaystyle 32\)

\(\displaystyle 27\)

\(\displaystyle 28\)

\(\displaystyle 29\)

Correct answer:

\(\displaystyle 32\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 85-27=58\)

\(\displaystyle 85-26=59\)

\(\displaystyle {\color{Teal} 85-32=53}\)

\(\displaystyle 85-29=56\)

\(\displaystyle 85-28=57\)

Because we are looking for the number that when subtracted from \(\displaystyle 85\) equals \(\displaystyle 53\), our correct answer is \(\displaystyle 32\)

Example Question #391 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 65=89-x\)

 

Possible Answers:

\(\displaystyle 26\)

\(\displaystyle 27\)

\(\displaystyle 25\)

\(\displaystyle 24\)

\(\displaystyle 28\)

Correct answer:

\(\displaystyle 24\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 89-27=62\)

\(\displaystyle 89-28=61\)

\(\displaystyle {\color{Teal} 89-24=65}\)

\(\displaystyle 89-25=64\)

\(\displaystyle 89-26=63\)

Because we are looking for the number that when subtracted from \(\displaystyle 89\) equals \(\displaystyle 65\), our correct answer is \(\displaystyle 24\)

Example Question #397 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 74=79-x\)

 

Possible Answers:

\(\displaystyle 4\)

\(\displaystyle 8\)

\(\displaystyle 6\)

\(\displaystyle 7\)

\(\displaystyle 5\)

Correct answer:

\(\displaystyle 5\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 79-7=72\)

\(\displaystyle 79-6=73\)

\(\displaystyle {\color{Teal} 79-5=74}\)

\(\displaystyle 79-4=75\)

\(\displaystyle 79-8=71\)

Because we are looking for the number that when subtracted from \(\displaystyle 79\) equals \(\displaystyle 74\), our correct answer is \(\displaystyle 5\)

Example Question #398 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 20=82-x\)

 

Possible Answers:

\(\displaystyle 65\)

\(\displaystyle 64\)

\(\displaystyle 63\)

\(\displaystyle 62\)

\(\displaystyle 61\)

Correct answer:

\(\displaystyle 62\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 82-61=21\)

\(\displaystyle 82-65=17\)

\(\displaystyle {\color{Teal} 82-62=20}\)

\(\displaystyle 82-63=19\)

\(\displaystyle 82-64=18\)

Because we are looking for the number that when subtracted from \(\displaystyle 82\) equals \(\displaystyle 20\), our correct answer is \(\displaystyle 62\)

Example Question #399 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 14=54-x\)

 

 

Possible Answers:

\(\displaystyle 37\)

\(\displaystyle 38\)

\(\displaystyle 39\)

\(\displaystyle 36\)

\(\displaystyle 40\)

Correct answer:

\(\displaystyle 40\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 54-38=16\)

\(\displaystyle 54-39=15\)

\(\displaystyle {\color{Teal} 54-40=14}\)

\(\displaystyle 54-37=17\)

\(\displaystyle 54-36=18\)

Because we are looking for the number that when subtracted from \(\displaystyle 54\) equals \(\displaystyle 14\), our correct answer is \(\displaystyle 40\)

Example Question #400 : Expressions & Equations

Which value for \(\displaystyle x\) would make the equation below true? 

\(\displaystyle 54=94-x\)

 

Possible Answers:

\(\displaystyle 41\)

\(\displaystyle 43\)

\(\displaystyle 40\)

\(\displaystyle 44\)

\(\displaystyle 42\)

Correct answer:

\(\displaystyle 40\)

Explanation:

We can use substitution to determine the value of \(\displaystyle x\)

\(\displaystyle 94-41=53\)

\(\displaystyle 94-42=52\)

\(\displaystyle {\color{Teal} 94-40=54}\)

\(\displaystyle 94-43=51\)

\(\displaystyle 94-44=50\)

Because we are looking for the number that when subtracted from \(\displaystyle 94\) equals \(\displaystyle 54\), our correct answer is \(\displaystyle 40\)

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