How do you Get this math problem??? Could someone explain answers and concepts please?

Question

The number after a variable in parentheses is the exponent

-2 (3x)2 (xy) (2x)2=

I got -24x5y but my book says it is -72x5y

PLEASE HELP ME!!

Answer 1

Since you have the 3x in parentheses, that means that both the 3 and the x gets the exponent, so 3 squared is 9. Likewise for the 2x squared, which equals 4(x^2). So altogether, you have:
-2 * 9(x^2) * xy * 4(x^2)
= -72x^5y
Hope this clears it up for you.

Answer 2

-2 (3x)^2 (xy) (2x)^2=

remember PEMDAS:
distribute exponents when necessary,
-2(9x^2)(xy)(4x^2)=

multiply
-72x^5y

when multiply exponents, you add the exponents,
for x, since 2+1+2 = 5 the exponent for x is 5

Answer 3

(3x)² = 9x² and
(2x)² = 4x²

those multiply together to make 36x^4, and you multiply that by xy and -2 to get

-72(x^5)y

Answer 4

-2 (3x)2 (xy) (2x)2
= -2 (9x2) (xy) (4x2)
= -72x5y

Answer 5

-2 (3x)^2 (xy) (2x)^2
=-2*9x^2*xy*4x^2
= -72x^5y...........-2*9*4 =-72

Answer 6

it's been a while... but I don't see how either could be correct... are you sure you've written it correctly??