Question

i solved 7x^2 – 63 = 0 which gave me x=9. How do i find the other x?

Answer 1

u did it wrong actually x^2=9, it means 2 values must satisfy this equation, these values are +3 and -3

Answer 2

Yeah, like wasiqss said. There's always two possible solutions for a squared value, since squaring a negative returns the same result as squaring the same positive - i.e. 3^2 = (-3)^2 = 9.

Answer 3

Well, "always" if a value isn't 0.

Answer 4

so i should have squared it after i got the 9?

Answer 5

why is it two 3's instead of one?

Answer 6

whenever you take the square root, there is a plus-minus condition

x^2 = n --> x = +-sqrt(n)

This is because the square of a negative number is positive
x^2 = 9 --> x = +-3
3^2 = 9
(-3)^2 = 9

Answer 7

thanks!