This would be much, much, much easier if you told us
what numbers you do have on each side of the scale now.
The idea (probably) is that the scale is balanced when
the numbers add up to the same amount on both sides.
So you need to put some numbers in the blanks that will either
add more to the side that has less, or subtract some from the side
that has more, to make both sides equal.
Kim drives = x
Terry drives = 2x
Jerry drives = 6x
Let us go through our answer choices and choose one.
A is incorrect because we are not being asked to add anything.
B is incorrect because it equals what all of the drivers drive.
2(x+3)
2*x + 2*3
2x + 6x
C is incorrect because we are not being asked to subtract.
D is correct because Jerry drives 3 times as much as terry.
2x*3
6x
So our final answer is D. 6x
Formula
A=bh divides by 2
SUBSTITUTE
45=b9 divided by 2
MULTIPLY/DIVIDE
You can either divide by 2 or multiply by 1/2 (gets the same answer)
9 x 1/2 = 4.5
DIVIDE
45 divides by 4.5 = 10
CHECK
A= 10 x 9 divided by 2 or multiply by 1/2 (same answer) = 45
Thus, the answer is 10.
I hope this helped you understand the process!