Answer:
Grace weighed 167 pounds before she started her exercise program.
Step-by-step explanation:
Given,
Weight lost by Grace = 45 pounds
Weight of Grace after exercise weeks = 122 pounds
Let,
x represents the weight of Grace before she started the exercise program.
Loss means subtraction, therefore,
We will subtract the lost weight from original weight.
Original weight - Weight lost = Weight after exercise weeks

Adding 45 on both sides


Grace weighed 167 pounds before she started her exercise program.
Answer: Choice C. 
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Explanation:
The domain is the set of all allowed x inputs.
Here we see that x = -3 is the smallest x value possible as it is from the left-most point. The graph goes on forever to the right, so there is no largest x value. Effectively infinity is the largest x value even though infinity is not a number.
We can say the domain is
which can be simplified to
or 
In short: x can be -3 or larger.
The answer to this is 42 degrees and 138 degrees.