One week jenna rented 4 dvds and 2 video games for $18, the next week she rented 2 dvds and 1 video game for 9$. find the rental costs for each video game and dvd. explain you answer.

To do this problem you have to create two equations. one would be 18=4x+3y
an the other would be 9=2x+y. in this eqaution X is the number of DVDs and Y is the number of Video games. Then you solve for Y in the second equation and you get y=-2x+9. After that you then input this equation in for the other equation and you will have 18=4x+3(-2x+9). you solve for X in this problem and then you take the answer of x and put it in for x in the other equation. 
so, 18=4x-6x+27
subtract 27 and add the 4x and -6x
-9=-2x
x=4.5
after this you put it in the other equation
9=-2(4.5)+y
multiply the -2 and 4.5
9=-9+y
add the 9
y=0

Do the math. she originally had 50 dollars on her gift card and she had 12 dollars left on her gift card after she finished her shopping spree. if you subtract 50 minus 12 you get thirty eight dollars as your answer. so therefore, ciara spent 38 dollars total o