Question

Solve the following system of equation graphically 2x+y=-1 and x+2y=4

Answer 1

As 2x + y = -1

Then,

y = - 1 - 2x

We can to replace on the bellow equation.

x + 2y = 4

x + 2.( -1 -2x) = 4

Doing the distributive

x + 2.(-1) + 2.(-2x) = 4

x -2 -4x = 4

-3x -2 = 4

-3x = 4 + 2

-3x = 6

x = 6/-3

x = -2
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Then, the value of y will be:

y = -1 -2x

y = -1 -2.(-2)

y = -1 + 4

y = 3