Question

Answer and work please help me

Answer 1

C.
3.1+1.28=4.38

$10 {}^{ - 3} + 10 ^{ - 4} = 10 {}^{ - 7}$
$4.38 \times {10}^{ - 7}$

Answer 2

The answer is A.

First, multiply 3.1 and 1.28

3.1 x 1.28 = 3.968

Next, add the exponents.

3 + 4 = 7

So you get 3.968 x 10^-7

Hope this helped! ♡