Question

4r(2) + 7r + 3s(2) 11r(3) + 3s(2)
Are these expressions equivalent?

Answer 1

does 4r(2) mean \( 4r^2 \)
if so, use an ^ to show it is an exponent like this: 4 r^2

Answer 2

Yes, that's what I meant. I didn't know up to make them like that off my computer. Are they equivalent?

Answer 3

they are asking if 4r^2 + 7r is the same as 11 r^3

if you tried with r=2, you would get 4*2^2 + 7*2 =? 11*2^3
or
4*4 + 14 =? 11*8
16+14= 88
30=? 88 ... It did not work.

so in general it is not true

Answer 4

but you should learn that you cannot combine terms that have different exponents.

x^1 + x^2 cannot be combined.

on the other hand
x^2 + x^2 can be combined (you have 2 x^2)

Answer 5

Okay. Could you help me with this one?
5mn - 8mn +13mn, simplify.

Answer 6

would it be 10mn?