Solving using 2 equations in two variable: Jason bought a total of 7 postcards for 1.80. If small cost 20 cents and the large ones cost 30 cents, how many postcards of each size did he buy?

Answer 1

answered here:

https://www.jiskha.com/display.cgi?id=1198461333

Answer 2

I am confused.

Answer 3

geesh, all they did was change the numbers.

here is a start:

small stamps ---- s
large stamps ---- l
s+l = 7 **
20s + 30l = 180 ---> 2s + 3l = 18 ***

solve the two equations ** and ***

or

small ones ---- s
larger ones ---- 7-s
20s+30(7-s) = 180
solve for s, then 7-s

Answer 4

thank you