Question

From 4a + 7b - 12c subtract 8a - 9b + 12d. I need help .

Answer 1

this is a tricky problem to start, but once you undertand it, it will be a lot easier!

we have to interprete the words into math symbols

From 4a + 7b - 12c subtract 8a - 9b + 12d.
From 4a + 7b - 12c - (8a - 9b + 12d)

do you see how I did that?

Answer 2

so how would i get my answer

Answer 3

you do it for each variable

Answer 4

we have this, and then we 'distribute' the '-' sign

4a + 7b - 12c - (8a - 9b + 12d)
4a + 7b - 12c - 8a + 9b - 12d

Answer 5

i had -4a + 16b - 24c - 24d but it was partial credit

Answer 6

4a-8a=-4a
7b-(-9b)= 7b+9b=16b
(-12c)-12c=-24c
-4a+16b-24c

Answer 7

what about for d?

Answer 8

do you see how you ended up with a
"- 24c - 24d"

it should just be
"- 12c - 12d"

Answer 9

so the answer is -4a+16b -12c - 12d?

Answer 10

yep, becuase we can only combine 'like terms'

Answer 11

thank you

Answer 12

^_^