How do you solve 2a + 3a - 6= - 21?

3 Answers
Mar 13, 2017

a=-3

Explanation:

2a+3a-6=-21

5a-6=-21

5a=-21+6

5a=-15

(5a)/5=-(15)/5

(cancel(5)a)/cancel(5)=-(15)/5

a=-3

Mar 13, 2017

See the entire solution process below:

Explanation:

First, combine the like terms on the left side of the equation:

2a + 3a - 6 = -21

(2 + 3)a - 6 = -21

5a - 6 = -21

Next, add color(red)(6) to each side of the equation to isolate the a term while keeping the equation balanced:

5a - 6 + color(red)(6) = -21 + color(red)(6)

5a - 0 = -15

5a = -15

Now, divide both sides of the equation by color(red)(5) to solve for a while keeping the equation balanced:

(5a)/color(red)(5) = -15/color(red)(5)

(color(red)(cancel(color(black)(5)))a)/cancel(color(red)(5)) = -3

a = -3

Mar 13, 2017

The answer to this question would be -3.

Explanation:

First of all, you might want to start off by combining like terms.

In this case, the terms 2a and 3a are like terms so, you add them together which leaves you with the following:

5a-6=-21

After that, you add 6 to both sides.

5a-6+6=-21+6 -> 5a=-15

Finally, divide both sides by 5, which leaves you with
a=-3

Thus, the answer is -3

Hope this helps! :-)