How do you solve x2 equals 7-4?

Answer 1

If you actually meant that as you wrote it:

x2 = 7 - 4

Then the answer is simple:

x2 = 7 - 4

∴ x2 = 3

∴ x = √3

If on the other hand, you actually wanted to say:

x2 = 7x - 4

Then you can find it this way:

x2 = 7x - 4

∴ x - 7x = -4

∴ x - 7x + (7/2)2 = -4 + (7/2)2

∴ (x - 7/2)2 = -16/4 + 49/4

∴ x - 7/2 = ± √(33/4)

∴ x = 7/2 ± √33/2

∴ x = (7 ± √33) / 2

Alternatively, if you meant to say:

x2 = 7 - 4x

Then the answer is:

x2 = 7 - 4x

∴ x2 + 4x = 7

∴ x2 + 4x + 4 = 7

∴ (x + 2)2 = 7

∴ x + 2 = ± √7

∴ x = -2 ± √7