<PRE><B>Question 193385</B>
let x and y be the number of of plasic and ceramic cups sold respectively
:
x+y=400............eq 1
3.5x+4y=1458.......eq 2
:
rewrite eq 1 to x=400-y and plug this value into eq 2
:
3.5(400-y)+4y=1458
:
1400-3.5y+4y=1458
:
.5y=58
:
y=116 ceramic cups
:
x=400-116=284 plastic cups
:
dollar value of plasic cups is 284(3.5)=$994
dollar value of ceramic cups is 116(4)=$464</PRE>