How is this correct?

3. a family is building a circular fountain in the backyard. the yard is rectangular and measures 7x by 6x and the fountain is going to be circular with a radius of 2x. once the fountain is build, what will be the area of the remaining yard?
a. 38x^2
b. [x] 2x^2 (21 _ 2pi)
c. 42x^2 _ 2pix^2
d. 38pix^2

Tanya has $42 to spend at the dolphin island store. tshirts sell for $7 each and a pair of sunglases sells for $6.tanya buys 3 tshirts. how many pairs of sunglases can she buys with the amount of money she has left

With: label the vertices and all the elements needed. find x

Dexter read 11 science fiction books and 5 history books. lena read 9 science fiction books and 4 history books. compare the students’ ratios of science fiction books to history books. 1. determine the ratios’ form:    science fiction books to history books 2. write the ratios as fractions:    dexter: 115; lena: 94 3. rewrite with a common denominator. 4. compare. 5. answer the question. determine which shows the correct comparison of the ratios for this problem.