First, before multiplying to cancel the fraction, let's isolate x by subtracting both sides by 3:
b/9 < 1
To cancel out the fraction, we multiply both sides by 9:
x < 9
D. 10 is your answer.
In order to solve a proportion, you cross multiply.
In this case it will be 40=4x
Solve for x is 10. Therefore D is your answer.
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ANSWER
-2 shift the graph of the basic function down by 2 units.
EXPLANATION
The given cosine function is:

This equation can be rewritten as:

We compare this to

The effect d has on the graph is that, it shifts the graph up by d units.
If d is negative the graph shifts down by d units.
Since d=-2, the graph will shift down by 2 units.
Of course it can. It always is if 'x' is less than 2.