How do you solve the system y=2-xy=2x and 5=y+2x5=y+2x using substitution?

1 Answer
May 21, 2015

y=2-xy=2x --------------(1)

5=y+2x5=y+2x ---------------(2)

Substituting yy from the first equation into the second one gives us:

5 = (2-x) + 2x5=(2x)+2x

5 = 2 - x + 2x5=2x+2x

5 = 2 + x5=2+x

Transposing 2 to the left hand side gives us :

5-2 = x52=x

color(green)(x = 3x=3

Substituting x = 3x=3 in the first equation will give us :

y = 2 - 3y=23

color(green)(y = -1y=1

The solution to both these equations :x = 3; y = -1x=3;y=1

Verify :

Substitute the values of x and yxandy in both the equations to see if they are satisfied