7x+9
5x+2x= 7x
5+4=9
7x + 9 is the result when combining like terms.
Answer:
120
Step-by-step explanation:
20% of 600
= 120 girls
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.
They are not similar, both of the triangles do not add up to the same number.
The original price was $64
Hope this helps:)