What are the solution to the equation .4x ^(2) + 8x = 9

Question

What are the solution to the equation .
`4x ^(2) + 8x = 9`

Answer 1

4x^2 + 8x = 9

Write the equation in the form:

ax^2+bx + c = 0

4x^2 +8x - 9 = 0

Where:

a =4

b= 8

c= -9

Apply the quadratic formula:

`\frac{-b\pm\sqrt[]{b^2-4\cdot a\cdot c}}{2\cdot a}`

Replace:

`\frac{-8\pm\sqrt[]{8^2-4\cdot4\cdot-9}}{2\cdot4}`
`\frac{-8\pm\sqrt[]{64+144}}{8}`
`\frac{-8\pm\sqrt[]{208}}{8}`
`\frac{-8\pm4\sqrt[]{13}}{8}`
`-1\pm\frac{\sqrt[]{13}}{2}`