I need help with some math questions!! Any help would be appreciated!!?

Question

1) Simplify:

(a) (ax^2)(-2ax)(-a^2) (b) 1/2 * 3.14 + 2/3 * 3.14 - 3.14

2) Multiply. Write the product in scientific notation.
(8.1 * 10^-6) (9 * 10^10)

Please show all your work.

Answer 1

1) (a) (ax^2)(-2ax)(-a^2)
= (-2)(-1) . a(a)(a^2) . (x^2)(x)
= 2a^4x^3.

(b) 1/2 * 3.14 + 2/3 * 3.14 - 3.14
= 3.14(1/2 + 2/3 - 1)
= 3.14(3/6 + 4/6 - 6/6)
= 3.14(1/6)
= 1.57 / 3.

2) (8.1 * 10^-6) (9 * 10^10)
= (8.1*9) *10^(-6+10)
= 72.9 * 10^4
= 7.29 * 10^5.

Answer 2

(1a) (ax^2)(-2ax)(-a^2)
= a * x^2 * (-2a) * x * (-a^2)
= a * (-a^2) * (-2a) * x^2 * x
= a * a^2 * 2a * x^2 * x
= 2a^4 * x^3
= 2(a^4)(x^3)

(1b) 1/2 * 3.14 + 2/3 * 3.14 - 3.14
= 3.14*(1/2 + 2/3 - 1) (Since 3.14 is the common factor, so just take it out and place it at the front)
= 3.14*(3/6 + 4/6 - 6/6)
= 3.14*(1/6)
= 0.523 (corrected to 3 sig. fig.)

(2) (8.1 * 10^-6) (9 * 10^10)
= 8.1 * 10^(-6) * 9 * 10^10
= 8.1 * 9 * 10^(-6) * 10^10
= 72.9 * 10^(-6+10)
= 72.9 * 10^4
= 7.29 * 10^5

Answer 3

2. (8.1*10^-6) (9*10^10)
(8.1)(9)=72.9
-6+10=4
72.9*10^4