Question

How do you solve the equation `5x+12=-3x-4`?

Answer 1

`x=-2`

Explanation:

Collect terms in x on the left side of the equation and numeric values on the right side.

add 3x to both sides.

`5x+3x+12=cancel(-3x)cancel(+3x)-4`

`rArr8x+12=-4`

subtract 12 from both sides.

`8xcancel(+12)cancel(-12)=-4-12`

`rArr8x=-16`

To solve for x, divide both sides by 8

`(cancel(8) x)/cancel(8)=(-16)/8`

`rArrx=-2`

`color(blue)"As a check"`

Substitute this value into the equation and if the left side is equal to the right side for this value then it is the solution.

`"left side "=(5xx-2)+12=-10+12=2`

`"right side "=-(3xx-2)-4==6-4=2`

`rArrx=-2" is the solution"`