Algebra 1 : Linear Equations

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #11 : How To Write Expressions And Equations

Solve by substitution method:

 

Possible Answers:

Correct answer:

Explanation:

From the second equation and by solving for  in terms of  we get

Replacing  in the first equation with

we get

Solving for  one gets

 

Replacing  with 4 in the above equation:

Hence the solution to the above system of linear equations is .

Example Question #12 : How To Write Expressions And Equations

Solve the following system of linear equations by the elimination method:

Possible Answers:

Correct answer:

Explanation:

We would like to eliminate .

Hence we multiply the first equation by  which gives us the following equations:

 

Adding the above two equations eliminates the variable . We are left with:

and so

Replacing  with  in the original equation gives us

solving for  gives us

Hence the solution is .

Example Question #931 : Algebra 1

For the following two linear equations determine whether the two lines are  __________:

 

(1) parallel

(2) perpendicular

(3) neither

(4) dependent

Possible Answers:

Parallel

Dependent

Neither

None of the above

Perpendicular

Correct answer:

Dependent

Explanation:

These two equations represent the same line and they "cross' at infinitely many points.  Therefore these systems are dependent.

Example Question #12 : How To Write Expressions And Equations

 

Possible Answers:

Correct answer:

Explanation:
 



 
 

Example Question #932 : Algebra 1

Which of the following sentences translates to the algebraic equation  ?

Possible Answers:

Eight multiplied by the difference of three and a number is equal to forty.

The product of three and a number less eight is equal to forty.

Eight multiplied by the difference of a number and three is equal to forty.

The product of eight and a number subtracted from three is equal to forty.

Three subtracted from the product of eight and a number is equal to forty.

Correct answer:

Eight multiplied by the difference of a number and three is equal to forty.

Explanation:

The expression on the left shows eight being multiplied by an expression in parentheses; that expression is the difference of an unknown number and three. The whole right expression is therefore worded as "Eight multiplied by the difference of a number and three"; the equality symbol and the forty round out the answer.

Example Question #933 : Algebra 1

Which of the following sentences translates to the equation  ?

Possible Answers:

Five divided into the difference of a number and nine is equal to eighty.

Five subtracted from the quotient of a number and nine is equal to eighty.

Nine subtracted from the quotient of a number and five is equal to eighty.

Nine divided by the difference of a number and five is equal to eighty.

Five divided by the difference of a number and nine is equal to eighty.

Correct answer:

Five divided into the difference of a number and nine is equal to eighty.

Explanation:

 can be written as "the difference of a number and nine"; the expression on the left shows that difference being divided by five, or, alternatively stated, "five divided into the difference of a number and nine". "Is equal to eighty " rounds out the sentence.

Example Question #934 : Algebra 1

In a room full of 60 people, 32 are women and 20 have blonde hair. Of the men, 16 do not have blonde hair. How many blonde women are in the room?

Possible Answers:

Correct answer:

Explanation:

First, calculate the total number of men.

Next, calculate the number of blonde men.

Now we can calculate the number of blonde women.

Example Question #22 : How To Write Expressions And Equations

A train travels for 2.5 hours at 60mph. For the next hour, the train travels at 40mph. How far does the train travel over the course of 3.5 hours?

Possible Answers:

Correct answer:

Explanation:

Use the distance equation, where is distance (mi),  is rate (mph), and  is time (h). In this instance, the train is traveling in two segments, so we will add the distances traveled during each segment.

The first rate is 60mph, and the first time is 2.5 hours. The second rate is 40mph, and the second time is 1 hour.

Example Question #23 : How To Write Expressions And Equations

The sum of two numbers is forty, and one number is three less than twice the other number.

Write an equation that represents this sentence.

Possible Answers:

Correct answer:

Explanation:

Suppose one number is .

The other number is "three less than twice the other number." Twice our other number is , and three less than twice this number is .

We are told that the sum of these two numbers is forty.

Now we can simplify.

Example Question #24 : How To Write Expressions And Equations

Represent this number in scientific notation:

Possible Answers:

Correct answer:

Explanation:

Write this number with the decimal point after it.

Move the decimal point to the position after the first nonzero digit, which here is the 1. Note that the resulting number, after truncating the trailing zeroes, is 

.

Also note that the number of places the decimal point moved is 23. Since the point was moved left the exponent will be 23, and the correct choice is 

.

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