Question

Use the Quadratic Formula to find the exact solutions of x2 + 7x − 4 = 0. x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a x equals negative 7 plus or minus the square root of 33, all over 2 x equals negative 7 plus or minus the square root of 65, all over 2 x equals 7 plus or minus the square root of 65, all over 2 x equals 7 plus or minus the square root of 33, all over 2

Answer 1

B

Explanation:

Our equation is x² + 7x - 4 = 0. We need to use the quadratic formula, which states that for a quadratic formula of the form ax² + bx + c = 0, then the zeroes/solutions are:
`x=(-b+√(b^2-4ac) )/(2a)` or
`x=(-b-√(b^2-4ac) )/(2a)`.

Here, a = 1, b = 7, and c = -4. Plug these in:

`x=(-b+√(b^2-4ac) )/(2a)`

`x=(-7+√(7^2-4*1*(-4)) )/(2*1)=(-7+√(49+16) )/(2) =(-7+√(65) )/(2)`

OR

`x=(-b-√(b^2-4ac) )/(2a)`

`x=(-7-√(7^2-4*1*(-4)) )/(2*1)=(-7-√(49+16) )/(2) =(-7-√(65) )/(2)`

Thus, the answer is B.