Question

Can someone please help me with this question? I will fan and give a medal...
Simplify (3a-4)-(7a-4)
a. -4a - 8
b. -4a
c. -4a + 8
d. 10a

Answer 1

the tricjiest part is to distribute the negative over the (7a - 4)
its the same as -1(7a - 4) which equals -1*7a -1*-4

Answer 2

so we have
3a - 4 -1*7a -1*-4
can you continue?

Answer 3

1*7=7
1*-4=-4
3a-4-7a-4
3a-7a-4-4
so a.-4a - 8?

Answer 4

no
-1* 7a = -7a ( - * + = -)
-1*-4 = + 4 ( when 2 negatives are multiplied the answer is a positive)

Answer 5

ooh so would it be c.-4a + 8?

Answer 6

3a - 4 - 7a + 4 - bring like terms together
= 3a - 7a - 4 + 4

Answer 7

3a - 71 = -4a that is correct but its not + 8 . Can you work out - 4 + 4?

Answer 8

* 3a - 7a = -4a

Answer 9

-4 + 4 = 4 - 4 = ?

Answer 10

0

Answer 11

correct
so which is the correct choice?

Answer 12

b. -4a

Answer 13

we needn't write 0


yes -4a

Answer 14

oh ok, thank you very much!! you're very helpful!

Answer 15

yw