Question

Solve for B: square root b^4/25 = 4.

A.) 2
B.) +/- 5 square root 2
C.) 3
D.) +/- 2 square root 5

I don't know how to do these so please show your work.

Thank you.

Answer 1

we cross multiply or multiply both sides by 25 to get b^4 = 100

sqrt of both sides gives us sqrt b^4 = sqrt 100 =
sqrt b^2 * b^2 = 10

b^2 = 10

b = +/- sqrt 10

which is roughly equal to +/- 3.1623...

Answer 2

√(b^4/25) = 4
b^2/5 = 4
b^2 = 20
b = ±√20, but since 20=4*5,
b = ±2√5

Answer 3

So which is it?

Answer 4

woops Steve is right, I did not see the sqrt before the equation.

So we get 16 = b^4/25

Simplifying we get 25*16 = 400

b^4 = 400

b^2 = 20

so, b^2 = sqrt 2^2 * 5

so, b = +/- 2 sqrt 5

answer is D

Sorry for inconvenience

Answer 5

*Sorry for any inconveniences caused to you.

Answer 6

Thank you for all your help...I appreciate it.