Which expression is the best estimate of Four-fifths times 22.01?

One-fifth times 20
Four-fifths times 20
4 × 20
5 × 20
Please awnserill give brainliest

1) if x^2=40, what is the value of x? a) +- 80 b) +- 20 c) +- square root of 80 d) +- square root of 40 2) solve x^2= -169 a) undefined b) 13 c) +- 13 d) -13 3) a square rug covers 79 square feet of floor. what is the approximate length of one side of the rug? (approximate to the nearest hundredth foot) a) 8.86 feet b) 8.87 feet c) 8.88 feet d) 8.89 feet