Question

Use the distributive property to simplify the expression below:
5t − 7(3 + t)

a. 12t-21
b. 12t-14
c. -2t-21
d. -2t+21

Answer 1

Distributive property: a(b + c) = ab + ac.
Why not use it?

Answer 2

so the a=5t-7
and the 3+t is the b+c?

Answer 3

No, leave out 5t for now, we'll deal with that later.
a = -7, b=3 and c = t

Answer 4

okay so
-7 X 3 + -7t ?

Answer 5

-21 + -7t..?

Answer 6

Yes, and -7*3=-2.
Now, remember you also have 5t lying around somewhere...

Answer 7

how is -7*3 = -2? shouldn't it be -21?

Answer 8

...

Answer 9

Of course, it is a typo, sorry!

Answer 10

lol okay, so now i have -21 + -7t right? and a 5t laying around somewhere..?

Answer 11

Right: 5t -7(3+t) = 5t-21-7t=...

Answer 12

-2t-21

so.. c

Answer 13

Thanks so much!!

Answer 14

YW!