How do you simplify (2+sqrt(x)) / (sqrt(2 x)+sqrt(8)) ?

2 Answers

sqrt2

Explanation:

When working a problem such as this, keep in mind that if we take something (like our denominator) that has the form of a+b, we can multiply by a-b and we'll end up with a^2-b^2. And so:

(2+sqrtx)/(sqrt(2x)+sqrt8)(1)

(2+sqrtx)/(sqrt(2x)+sqrt8)((sqrt(2x)-sqrt8)/(sqrt(2x)-sqrt8))

((2+sqrtx)(sqrt(2x)-sqrt8))/((sqrt(2x)+sqrt8)(sqrt(2x)-sqrt8))

(2sqrt(2x)-2sqrt8+sqrtxsqrt(2x)-sqrtxsqrt8)/(2x-8)

Now for some simplification in the numerator. Remember that sqrt8=2sqrt2:

(2sqrt(2x)-2(2sqrt2)+sqrt(2x^2)-2sqrt(2x))/(2x-8)

(-4sqrt2+xsqrt2)/(2x-8)

(sqrt2(x-4))/(2(x-4))

sqrt2/2

Remember that (pmsqrt2)^2=2

sqrt2/(sqrt2)^2=sqrt2

and

sqrt2/(-sqrt2)^2=sqrt2

Jul 2, 2018

sqrt(2)/2 = 1/sqrt(2)

Explanation:

Given: (2 + sqrt(x))/(sqrt(2x) + sqrt(8))

Multiply both the numerator and the denominator by the conjugate of the denominator, which is basically multiplying the expression by 1.

The conjugate is a factor that when multiplied, cancels the middle term. The conjugate of sqrt(2x) + sqrt(8) is sqrt(2x) - sqrt(8).

(2 + sqrt(x))/(sqrt(2x) + sqrt(8)) * (sqrt(2x) - sqrt(8))/(sqrt(2x) - sqrt(8))

= (2 sqrt(2x)-2 sqrt(8) + sqrt(x) sqrt(2x) - sqrt(x)sqrt(8))/(sqrt(2x) sqrt(2x) - sqrt(8)sqrt(8))

Use the Radical rules: sqrt(a)sqrt(b) = sqrt(ab); " "sqrt(x)sqrt(x) = sqrt(x^2) = x

Simplify sqrt(8): " "sqrt(8) = sqrt(4*2) = sqrt(4)sqrt(2) = 2 sqrt(2)

=(cancel(2 sqrt(2x))-2*2 sqrt(2) + x sqrt(2) cancel(- 2 sqrt(2x)))/(sqrt(4x^2) - sqrt(64))

= (-4sqrt(2) + xsqrt(2))/(2x - 8) = (xsqrt(2) - 4sqrt(2))/(2x - 8)

Factor: " " (sqrt(2)cancel(x - 4))/(2cancel(x - 4))

(2 + sqrt(x))/(sqrt(2x) + sqrt(8))= sqrt(2)/2