Simplify the expression. write the answer using scientific notation. (9 x 10)^2(2 x 10)^10

a) 1.8 x 10^21
b) 1.8 x 10^13
c) 1.1 x 10^13
d) 1.1 x 10^21

B

Step-by-step explanation:

To multiply scientific notation, multiply each part of the number.

(9 x 10)^2(2 x 10)^10 = (9*2) * (10^ 2 + 10) = 18 * 10 ^ 12

Since scientific notation can only have a digit in the ones place from 1-9. 18*10^12 becomes 1.8*10^13.

The solution is B.

28

step-by-step explanation:

because that's the answer

if you was gonna solve for a, a is a   < -12