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21 votes
Simplify the expression below.
12a−8−5a+12

2 Answers

1 vote

Answer:

7a + 4

Explanation:

First, let's rewrite this expression to combine like terms:

12a – 8 – 5a + 12 — I bolded the constants and underlined the expressions with variables

12a – 5a – 8 + 12 — it looks a little easier regrouped, doesn't it?

The last two terms are easy, right?

12 – 8 = 4 — simplify with subtraction

We'll focus on the first two terms now. Let's rewrite the terms with variables attached to make the subtraction easier:

a(12 – 5) = a(7) = 7a

We could also think of it this way: multiplication is just repeated addition.

12a = a + a + a + a + a + a + a + a + a + a + a + a (we just add a to itself 12 times)

5a = a + a + a + a + a (we just add a to itself 5 times)

Subtracting this expression would then look like this:

a + a + a + a + a + a + a + a + a + a + a + a – (a + a + a + a + a)

a + a + a + a + a + a + a + a + a + a + a + aaaaaa

Five of the a values will cancel out, and to show this, we can rewrite the expression once more, like this:

aa + aa + aa + aa + aa + a + a + a + a + a + a + a

The five a values cancel out and leave us with this:

a + a + a + a + a + a + a

How many a values are added together now? Seven of them, right? We add a to itself 7 times. We can then rewrite that expression as 7a.

Using the [12 – 8 = 4] expression from above, we add the 4 to the 7a to find our final answer: 7a + 4

I hope this helps increase your understanding of the concept! Have a great day!

User Gilles Criton
by
4.2k points
3 votes

Explanation:

Given

12a - 8 - 5a + 12

= 7a + 4

Hope it will help :)

User DuduAlul
by
3.5k points