Question

Solve the system by substitution:
2x+3y=20
6x-y=20

Answer 1

2x + 3y=20
2x=20-3y ( BY TRANSPOSING 3y to RHS)
2x/2=(20-3y)/2
x=(20-3y)/2
PUT THE VALUE OF x IN THE EQUATION 2 :
6x-y=20
6((20-3y)/2) - y=20
(120-18y)/2 - y=20
(120-18y - 2y)/2=20
120-20y=40
transposing 120 to RHS
-20y=-80
y=4
and 6x-4=20
6x=24
x=4
hence x and y are equal to 4

Answer 2

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