Answer:
cool
Step-by-step explanation:
Answer:
-4x=4
Step-by-step explanation:
-4x+7=11 subtract 7 add to the 11 answer-4x=4
First we need to have same units before comparing them. That is, either both of them are in cm or both of them are in mm. So if we need to convert 12.5 cm to mm, we know that 1 cm =10 mm. So we have to find out how many mm are in 12.5 cm. And let 12.5 cm =x mm. So to find the value of x , we set a proportion and solve for x. That is

The units cancel out and we do cross multiplication. That is

x=125
So 12.5 cm =125 mm. Therefore the correct proportion is C.
The answer would be the first choice. 
Explanation: The reason for this is that the question was pretty much just asking what the area of the resulting two-dimensional cross section would be -the shape in gray- (which can be found by using the formula
. To add on, since the dimensions of the shape are already given (5 and 3) all you've to do is multiply: 3*5=15
That's how you get to the answer.