Question

Solve y =-2x
y = 3x + 5
by using substitution method

Answer 1

y = -2x

y = 3x + 5

<=> 3x + 5 = -2x

y = -2x

<=> 5x = -5

y = -2x

<=> x = -1

y = -2x

<=> x = -1

y = (-2)(-1) = 2

so (x; y) = (-1; 2)