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:
[tex]\frac{-b\pm\sqrt[]{b^2-4\cdot a\cdot c}}{2\cdot a}[/tex]
Replace:
[tex]\frac{-8\pm\sqrt[]{8^2-4\cdot4\cdot-9}}{2\cdot4}[/tex][tex]\frac{-8\pm\sqrt[]{64+144}}{8}[/tex][tex]\frac{-8\pm\sqrt[]{208}}{8}[/tex][tex]\frac{-8\pm4\sqrt[]{13}}{8}[/tex][tex]-1\pm\frac{\sqrt[]{13}}{2}[/tex]
