A store sells T-shirts for $10 each and jeans for $20 a pair. Anna spends $150 on T-shirts and jeans. She buys x T-shirts and y pairs of jeans.
The equation that represents the situation is . If Anna decides to buy only T-shirts and no jeans, she can buy T-shirts with the money she has.

Question

A store sells T-shirts for $10 each and jeans for $20 a pair. Anna spends $150 on T-shirts and jeans. She buys x T-shirts and y pairs of jeans.
The equation that represents the situation is . If Anna decides to buy only T-shirts and no jeans, she can buy  T-shirts with the money she has.

anonymous · Answer

x+y=150
multiply by the cost for each
solve x
$10x+$20y=$150

10x+20y-20y= 150 -20y
10x=-20y +150

10x/10=-20y +150/10
x=−2y+15

solve y
10x+20y+−10x=150+−10x
20y=−10x+150

20y/20=−10x+150/20
y=−1/2 x+15/2 
y= 0.5x + 7.5

Does this help?