Question

Which equation shows the quadratic formula used correctly to solve 7x2 = 9+ x for x?

Answer 1

x = (1 + sqrt(253))/14 or x = (1 - sqrt(253))/14

Explanation:

Solve for x:

7 x^2 = x + 9

Subtract x + 9 from both sides:

7 x^2 - x - 9 = 0

x = (1 ± sqrt((-1)^2 - 4×7 (-9)))/(2×7) = (1 ± sqrt(1 + 252))/14 = (1 ± sqrt(253))/14:

Answer: x = (1 + sqrt(253))/14 or x = (1 - sqrt(253))/14

Answer 2

This can also be explained as D on edg :)