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.

6 answers

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...
√(b^4/25) = 4
b^2/5 = 4
b^2 = 20
b = ±√20, but since 20=4*5,
b = ±2√5
So which is it?
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
*Sorry for any inconveniences caused to you.
Thank you for all your help...I appreciate it.
Similar Questions
  1. Use the quadratic formula to solve the equation. Give exact answers:2x^2 -1 = 6x. The choices are: a) -3 + square root(7)/2, -3
    1. answers icon 4 answers
  2. Add and Subtract Radicals Quick CheckMath 8 Q2 (Pre-Algebra) / Roots and Irrational Numbers add 2 square root 21 + 3 square root
    1. answers icon 1 answer
  3. Add and Subtract Radicals Quick CheckMath 8 Q2 (Pre-Algebra) / Roots and Irrational Numbers add 3 square root 21 + 7 square root
    1. answers icon 1 answer
  4. Express in simplest radical form.square root of, 3, x, end square root 3x ​ Answer Multiple Choice Answers square root of, 3,
    1. answers icon 1 answer
more similar questions