Y=6x 2x+3y=-20. (Solving by substitution)

Y=6x, 2x+3y=-20

Substitution means just plugging in another equation equal to a single variable in order to solve for the other variable, and then the first. In this case, the equation being plugged in is y=6x, so 6x will be put in place of y in the equation 2x+3y=-20.

2x+3 (6x) = - 20

2x+18x=-20

20x=-20

x=-1

And then x=-1 can be plugged into the original equation to find y. (And, if you wish, into the y = equation to check it.)

2 (-1) + 3y=-20

-2+3y=-20

3y=-20+2

3y=-18

y=-6

And to check it, we plug the two into the original y = equation.

y=6x

-6=6 (-1)

-6=-6

They are equal, so both check out.

x=-1, y=-6

This is straight forward:

y = 6x ... (i)

2x + 3y = - 20 ... (ii)

We simply substitute (i) into (ii)

2x + 3 (6x) = - 20

2x + 18x = - 20

20x = - 20

x = - 20/20

x = - 1.

Recall y = 6x

y = 6 (-1) = - 6.

x = - 1, y = - 6.