Question

Benny spent half of his allowance going to the movies. He washed the family
car and earned 8 dollars. What is his weekly allowance if he ended with
13 dollars ?

Answer 1

if he got paid $8 then you’d have to do 13-8=5 and then double it so that gives you 10

Answer 2

Let it be x

He spent x/2 dollars then

$\\ \sf\longmapsto \dfrac{x}{2}+8=13$

$\\ \sf\longmapsto \dfrac{x+16}{2}=13$

$\\ \sf\longmapsto x+16=13(2)=26$

$\\ \sf\longmapsto x=\dfrac{26}{16}$

$\\ \sf\longmapsto x=\dfrac{13}{8}$

$\\ \sf\longmapsto x=1.6$

$\\ \sf\longmapsto Weekly allowance=13+7(1.6)$

$\\ \sf\longmapsto 13+112=125$