Question

X+2y=4 and -x+y=-7 using substitution method

Answer 1

Explanation:

hello :

x+2y=4 ....(*)

-x+y=-7....(**)

by(*) : x = 4-2y

put this value in to (**) : -(4-2y)+y=-7

-4+2y+y = -7

3y = -3

y= -1

but : x=4-2y so : x=4-2(-1)=6

conclusion : one solution (6 , -1)

Answer 2

1. x=4-2y

2.x=7+y






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