Question

What is the solution of the equation x^2+10x+75=0

Answer 1

x = -12.071 (3dp)

x = -11.036 (3dp)

Explanation:

Step 1: Apply the quadratic formula

(-b±(
`√(b²-4ac)`)) / 2a

a = 1 (x²)

b = 10 (10x)

c = 75 (75)

(-10±(
`√(10²- 4 x 1 x 75)`)) / 2 x 1

Step 2: Simplify

(-10±(
`√(-200)`)) / 2

Step 3: Solve the equation

You must replace ± with first a + then a -.

(-10+(
`√(-200)`)) / 2 = -12.071 (3dp) = x

(-10-(
`√(-200)`)) / 2 = -11.036 (3dp) = x

Hope this helps!