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! :-)