Want to check a problem?

Question

The problem is:

solve A = B^2 - 4B for B.

I got B = the square root of (A+4B).
is that the simplest form? because it seemed just too easy to get that answer.

I figured I could also try to get B in simplest form by working with the 4B and not the B^2. When I did that I got
B = (B^2 - A) / 4

Which one is the right answer? Or are both wrong?
Thanks.

Answer 1

a = b^2 - 4b
a + 4b = b^2
(a/b) + 4 = b

or

a = b(b - 4)
a/(b-4) = b

Answer 2

When you solve for a specific variable in an abstract equation, you should not get the variable you are solving for (in this case B) in the solution. Since B is quadratic (to the second power) you need to use the quadratic formula. First rewrite the equation as B² - 4B - A = 0. The coefficients of the quadratic are a = 1, b = -4, and c = -A.

B = (4 +/- sqrt[(-4)² - 4(1)(-A)])/(2*1)

B = (4 +/- sqrt(16+4A))/2

B = (4 +/- sqrt[4(4+A)])/2

B = (4 +/- 2sqrt(4 + A))/2

B = 2 +/- sqrt (4 + A)

I hope this helps

Answer 3

A = B^2 - 4B
To solve it for B
consider this as a quadratic equation B
then solve it
we obtain

B = 2+sqrt(4+A), B = 2-sqrt(4+A)
yours both answers are wrong

Answer 4

B= 4+sqt16+4A/ 2 and B = 4- sqt 16+4A/ 2

using quadratic formula

Answer 5

B^2 -4B -A = 0
B = [4 +/- sqrt(4^2-4(1)(A))]/2
B= 4 +/- sqrt(16-4A)]/2
B = 2 +/- sqrt(4-A)