PLEASE HELP ME PLEASE IM TIMED

Set up an equation to solve.

$8.50x (since it is the rate of change) + $12 (flat fee) = total money earned (or y). In this case, we have the total, amount, and are looking for x. Plug $139.50 into the equation.

$8.50x + $12 = $139.50

Now, solve for x.

$8.50x + $12-12 = $139.50-12  > $8.50x = $127.5

$8.50/8.50x = $127.5/8.50 > x = 15

So, the correct answer is D. Olivia babysat for 15 hours.

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)