Question

Solve the following system of equations using substitution. What is the value of y?
2x+3y=105
x+2y=65
I somehow got -1(4/6)x=-5. Can someone provide a clear explanation on how to do this?

Answer 1

x + 2y = 65 ==> x = -2y + 65
now sub -2y + 65 in for x in the other equation
2x + 3y = 105
2(-2y + 65) + 3y = 105 -- distribute
-4y + 130 + 3y = 105 -- subtract 130
-4y + 3y = 105 - 130 -- combine like terms
-y = - 25
y = 25

x + 2y = 65
x + 2(25) = 65
x + 50 = 65
x = 65 - 50
x = 15

check..
x + 2y = 65 2x + 3y = 105
15 + 2(25) = 65 2(15) + 3(25) = 105
15 + 50 = 65 30 + 75 = 105
65 = 65 (correct) 105 = 105 (correct)

I know you just needed to find y, but I found them both in order to check them.
y = 25 and x = 15

Answer 2

do you understand, or do you have any questions ?

Answer 3

I get it know, thanks a bunch :)

Answer 4

anytime :)