121,675 views
13 votes
13 votes
Why does -2(x + 3y) = 18 equal y=-3-x/3? Please helppp

User Susanne
by
2.8k points

2 Answers

14 votes
14 votes

For this I would isolate y from the beginning.

Heres how I would solve it:

-2(x + 3y) = 18 --> 18 divided by (-2) is (-9), so (x + 3y) must be equal to (-9)

x + 3y = -9 --> now I would begin to isolate for y:

3y = -9 -x

y = (-9-x) ÷ 3 --> dividing each term by 3 would give me:

y = -3 - x/3 --> x stays the same because it doesn't have a definite answer.

Hope this helps (〃▽〃)

User Andreas Herd
by
3.6k points
26 votes
26 votes

Explanation:

You're asking why


{- 2(x + 3y) = 18} = y = - 3 - (x)/(3)

let's transpose the first equation for y

-2x-6y=18

-6y=18+2x

6y=-18-2x

y=-18/6-2x/6

y=-3-⅓x as required

User Allene
by
2.6k points