Answer:
-10.5 deg
Step-by-step explanation:
Yesterday's temp = 7-1/2 deg (or 7.5 deg)
Today's temp = -3 deg
net change = today's temp - yesterday's temp
= -3 - 7.5 = -10.5 deg
Let i = sqrt(-1) which is the conventional notation to set up an imaginary number
The idea is to break up the radicand, aka stuff under the square root, to simplify
sqrt(-8) = sqrt(-1*4*2)
sqrt(-8) = sqrt(-1)*sqrt(4)*sqrt(2)
sqrt(-8) = i*2*sqrt(2)
sqrt(-8) = 2i*sqrt(2)
<h3>Answer is choice A</h3>
