Question

Help me in this

Select all names that apply to the number.
What is the value of x if x2 = 36/81?

A) 2/3

B) 4/9

C) ± 2/3

D) ± 4/9

Answer 1

Hello from MrBillDoesMath!

Answer: C)

Discussion:

To solve x^2 = 36/81 take the square root of both sides.

x = square root of (36/81)

As 36 = 6*6 and 81 = 9*9,

x = square root of (6*6)/ (9.9) or 6/9

But 6 and 9 share the common factor "3" so

x = 6/9 = (2*3)/(3*3) = 2/3

The last equality was gotten by cancelling the common factor 3.

Regards, MrB