I need someone to explain to me how I got the incorrect answer:
A family is having a pool built in their backyard. If the yard is rectangular and measures 7x by 6x, and the pool is circular with a radius of 2x, how much of the yard will be left over after the pool is built?

Question

I need someone to explain to me how I got the incorrect answer:
A family is having a pool built in their backyard. If the yard is rectangular and measures 7x by 6x, and the pool is circular with a radius of 2x, how much of the yard will be left over after the pool is built?

anonymous · Answer

My answer: 42x^2 - 2(pi)x^2
The correct answer: 42x^2 - 4(pi)x^2
Why does the answer have a 4 instead of a 2?

anonymous · Answer

@gorv can you help with this quick question?

anonymous · Answer

@Hero ?

anonymous · Answer

you probably wrote or typed the answer wrong

phi · Answer

radius of 2x

r^2 means r*r  or 2x*2x=  4x^2

phi · Answer

area of a circle is pi * r^2

anonymous · Answer

Ahhhhh okay thank you @phi