We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 85-30=55$

$\displaystyle 85-31=54$

$\displaystyle 85-32=53$

$\displaystyle {\color{Teal} 85-29=56}$

$\displaystyle 85-28=57$

Because we are looking for the number that when subtracted from $\displaystyle 85$ equals $\displaystyle 56$, our correct answer is $\displaystyle 29$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 89-22=67$

$\displaystyle 89-23=66$

$\displaystyle 89-24=65$

$\displaystyle {\color{Teal} 89-25=64}$

$\displaystyle 89-26=63$

Because we are looking for the number that when subtracted from $\displaystyle 89$ equals $\displaystyle 64$, our correct answer is $\displaystyle 25$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 79-2=77$

$\displaystyle 79-6=73$

$\displaystyle 79-5=74$

$\displaystyle {\color{Teal} 79-4=75}$

$\displaystyle 79-3=76$

Because we are looking for the number that when subtracted from $\displaystyle 79$ equals $\displaystyle 75$, our correct answer is $\displaystyle 4$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 82-61=21$

$\displaystyle 82-60=22$

$\displaystyle 82-62=20$

$\displaystyle {\color{Teal} 82-63=19}$

$\displaystyle 82-64=18$

Because we are looking for the number that when subtracted from $\displaystyle 82$ equals $\displaystyle 19$, our correct answer is $\displaystyle 63$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 94-41=53$

$\displaystyle 94-42=52$

$\displaystyle 94-40=54$

$\displaystyle {\color{Teal} 94-39=55}$

$\displaystyle 94-38=56$

Because we are looking for the number that when subtracted from $\displaystyle 94$ equals $\displaystyle 55$, our correct answer is $\displaystyle 39$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 54-38=16$

$\displaystyle 54-39=15$

$\displaystyle 54-35=19$

$\displaystyle {\color{Teal} 54-37=17}$

$\displaystyle 54-36=18$

Because we are looking for the number that when subtracted from $\displaystyle 54$ equals $\displaystyle 17$, our correct answer is $\displaystyle 37$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 27-27=0$

$\displaystyle 27-26=1$

$\displaystyle 27-25=2$

$\displaystyle {\color{Teal} 27-23=4}$

$\displaystyle 27-24=3$

Because we are looking for the number that when subtracted from $\displaystyle 27$ equals $\displaystyle 4$, our correct answer is $\displaystyle 23$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 99-52=47$

$\displaystyle 99-53=46$

$\displaystyle 99-51=48$

$\displaystyle {\color{Teal} 99-50=49}$

$\displaystyle 99-49=50$

Because we are looking for the number that when subtracted from $\displaystyle 99$ equals $\displaystyle 49$, our correct answer is $\displaystyle 50$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 39-17=22$

$\displaystyle 39-18=21$

$\displaystyle 39-19=20$

$\displaystyle {\color{Teal} 39-20=19}$

$\displaystyle 39-16=23$

Because we are looking for the number that when subtracted from $\displaystyle 39$ equals $\displaystyle 19$, our correct answer is $\displaystyle 20$

We can use substitution to determine the value of $\displaystyle x$. 

$\displaystyle 45-9=36$

$\displaystyle 45-10=35$

$\displaystyle 45-11=34$

$\displaystyle 45-12=33$

$\displaystyle {\color{Teal} 45-13=32}$

Because we are looking for the number that when subtracted from $\displaystyle 45$ equals $\displaystyle 32$, our correct answer is $\displaystyle 13$