126a(-1/9a)(1/7a cubed) and the answer to this in my book says -2a to the fith. How does it work, i've tried multiple times.

Answer 1

Is it 1/(7a)³ OR
1/7(a)³

Answer 2

(1/7a then the three)

Answer 3

For 126*(-1/9a)*(1/7a)³, I don't get anything like -2a⁵.

Answer 4

but it's 126a(-1/9a)(1/7a3)

Answer 5

Let me write it different it's
126a times negative one ninth "a" times one seventh "a cubed"

and the answer says negative 2a to the fifth

Answer 6

Must be

126 a (-1/9)a (1/7) a^3

Answer 7

That gives you the answer you are looking for.

Answer 8

126 a (-1/9)a (1/7) a^3
is
[ -126/ (9*7) ] (a*a*a^3)

-2 a^5

Answer 9

You REALLY need to learn to use parentheses for these problems because what you have written here is not what you started with. I will write what I now think the problem is.
126a(-1/9)a*(1/7)*a³
= -1*(126/9*7) = 2
a*a*a³ = a⁵
So the book is correct. The answer is -2a⁵