Solve for x: 5x+20=2x-4

Answer 1

Solve for x: 5x + 20 = 2x – 4

Detailed Solution:

5x + 20 = 2x – 4 ==> 5x – 2x = -20 – 4 ==> 3x = -24 ==> x = -24/3 ==> x = -8

Answer 2

Solving for a variable means we want it by itself on one side of the equal sign, x = something in this case. We do this by using opposite operations, always doing the same operation to both sides so they stay equal.

5x + 20 = 2x - 4

First we want to "move" all terms with x onto the same side. I'll move 2x to the left side by subtracting (2x - 2x = 0, so it's gone from the right side).

5x + 20 - 2x = 2x - 4 - 2x

3x + 20 = -4

Now, we move any terms without x to the opposite side than x.

3x + 20 - 20 = -4 - 20

3x = -24

Almost there! We need to isolate x, and it's multiplied by 3, so we'll divide both sides by 3 (3x/3) = 1x but we don't call me "1 David).

3x/3 = -24/3

x = -8

Aaaaaaand done, though we should check our work.

5(-8) + 20 = 2(-8) - 4

-40 + 20 = -16 - 4

-20 = -20

Hey, that's true, so we were correct! Keep it up!

Answer 3

5x+20=2x-4

There a couple of ways to go about this, but this is just the way I prefer to use. First, I am going to add 4 to both sides of the equation. This will result in:

5x+24=2x

Next, we have to isolate the x. I am going to do this by subtracting 5x on both sides of the equation. This results in:

24=-3x

Finally, since -3 is being multiplied to x, we have to divide -3 on both sides. This ultimately results in:

-8=x. Meaning that -8 is the answer.