Question

Want to double check on this: 3(x + 5) - 2(x + 2) = 20
I got 1 as the answer. Is that right?

Answer 1

na. The answer should be x=9

Answer 2

If you doubt your answer then put 1 in place of x in your equation and check whether you are getting both sides equal or not...

Answer 3

3(1 + 5) - 2(1 + 2) = 20

18 - 6 = 20

12 = 20 ( false)


This means 1 is not the right answer..

Answer 4

Darn! do you know what I might have done wrong?

Answer 5

Let us go step by step...

Answer 6

Distribute 3 and 2 to their respective brackets first...

Can you do that??

Answer 7

\(3(x + 5) = ??\)

Answer 8

You could have made the mistake when you expanded the brackets... For example -2(x+2) is -2x-4

Answer 9

Wow! yeah I did...I didn't think it was going to be negative.

Answer 10

3x+15

Answer 11

\(-2(x + 2) = ??\)

Answer 12

-2x+4?

Answer 13

Nope here you have mistaken..

Answer 14

always look out for a negative if the number which you are multyplying the bracket with is negative. Do not leave out the negative sign

Answer 15

\[-2 ( x + 2) \implies -2 \times x + (-2) \times (2) \implies -2x + (-4) \implies -2x - 4\]

Answer 16

So that is where you went wrong @jewjewbri in -2(x+2)

Answer 17

Remember :

\(+(-) = \; \; -\)