math homework part 2?

Question

Solve: (a + 2)/4 = 1/a

Answer 1

Try cross-multiplying to get rid of the denominators:
(a + 2)/4 = 1/a
4 * [(a + 2)/4] = [1/a] * 4
--> a+2 = 4/a

a * (a+2) = (4/a) * a
--> a² + 2a = 4
--> a² + 2a - 4 = 0

We would want to find value(s) of a that'll make the whole thing 0. Can't figure how we'll factor that, so we'll try quadratic formula. Remember [-b +/- sqrt(b² - 4ac)] / 2a?

a = [-(2) +/- sqrt( (2)² - 4(1)(-4) )] / 2(1)
= [-2 +/- sqrt(4+16)] / 2
=[-2 +/- sqrt(20)] / 2
= [-2 +/- sqrt(4*5)] / 2
= [-2 +/- sqrt(4)*sqrt(5)] / 2
= [-2 +/- 2*sqrt(5)]/2
= (-2/2) +/- [2*sqrt(5)/2]
= -1 +/- sqrt(5)
= -1 - sqrt(5) and -1 + sqrt(5)

Answer 2

(a+2)/4=1/a
(a+2)/4=1/a
(a+2)=4/a
a(a+2)=4
a^2+2a=4
Then use Complete the square

Nathan™

Answer 3

Wow. We had the same techniques. the very optimal suited explanation for it rather is to remodel each and every of the operations into Multiplication. it rather is performed into : 6 x (a million/2) x (3) Any subject divided into 2 might desire to be switched over as greater suited right into a million/2 hence, getting the respond 9 even with way. 18 x a million/2 3 x 3 a million.5 x 6 performed.

Answer 4

(a + 2)/4 = 1/a
a=a
a(a+2)/4 = 1
4=4
a(a+2) = 4
a^2 + 2a - 4 = 0
plug into quadratic formula
a = sqrt(5) - 1
a = -sqrt(5) - 1
Hmmm...

Answer 5

ok.. i have been answering math ?'s all day and i am tired of explaining sooo...
the answer is 2. (i may have made a mistake but i am almost sure it's 2)