SOLUTION: Use substitution to solve for x and y 4x - y = -7 2x + 2y = 4

Algebra ->  Expressions-with-variables -> SOLUTION: Use substitution to solve for x and y 4x - y = -7 2x + 2y = 4      Log On


   

Question 61696This question is from textbook Alegbra Concepts and Applications
: Use substitution to solve for x and y
4x - y = -7
2x + 2y = 4 This question is from textbook Alegbra Concepts and Applications

Answer by jai_kos(139) About Me  (Show Source):
You can put this solution on YOUR website!
Given 4x - y = -7 --->(1)
2x + 2y = 4 --->(2)
Divide equation(2) by 2, we get
x + y = 2
x = 2 - y --->(3)
Substitue the equation(3) in equation(1), we get...
4(2-y) -y = -7
8 - 4y -y = -7
8 -5y = -7
-5y = - 7 - 8
-5y = -15
y = -15/ - 5
y = 3 --->(4)
Now substitue the value of y =3 in eqution(3), we get
x = 2 - 3 = -1
x =-1
Therefore we have the x =-1 and y = 3