Lucy’s family purchased one sweat shirt and four tee shirts for a total of $110. Mark’s family picked up three sweatshirts and four tee shirts for a total of $200. Write algebra equations for each purchase in the same way you did in problem one. Use your equations to find the cost of a tee shirt and a sweat shirt.

Question

hoblos · Answer

cost of sweat shirt =x
cost of a tee shirt = y

x+4y = 110
3x+4y = 200

hoblos · Answer

do you know how to solve it now?

anonymous · Answer

yes

anonymous · Answer

x+4y do i solve this equation?

hoblos · Answer

well you have to solve the whole system...

try subtracting the two equations.. what will you get?

anonymous · Answer

i got 110-4y

hoblos · Answer

x+4y = 110   --------- equation (1)
3x+4y = 200 --------- equation (2)

if you subtract you will get
|dw:1333824158182:dw|