Question

James has 19 phone cards worth either $20 or $15. how many of each does she have if the phone cards total $300?

Answer 1

300/19= 15

Answer 2

You have to set up a system of equation.
x+y=19
20x+15y=300

Solve for x and y.

Answer 3

x+y=19
20x+15y=300

-20x-20y=-380
20x+15y=300

Add the equations together
-5y=-80
y=16

Plug y=16 back into one of the equations
x+y=19
x+16=19
x= 19-16
x=3

So she has 3 of the $20 cards and 16 or the $15 cards.

Answer 4

ohh I see .. i was wrong then

Answer 5

Clearly explained stargirlzilin, Thank You.