Question

Solve 49x^2+64=0 by using square roots

Answer 1

x = ±i8/7

Explanation:

49x^2 +64 = 0

Subtract 64 from each side

49x^2 +64-64 = 0-64

49x^2 = -64

Divide by 49

49x^2/49 =-64 /49

x^2 = - 64/ 49

Take the square root of each side

sqrt(x^2) = ±sqrt(- 64/ 49)

x = ±sqrt(- 64/ 49)

We know sqrt( ab/c) = sqrt(a) sqrt(b)/sqrt(c)

x = ±sqrt(- 1) sqrt(64)/( 49)

We know that the sqrt(-1) = i

x = ±i8/7