Answer:
x = (-1 ±[tex]\sqrt{145}[/tex] )/8
Step-by-step explanation:
Quadratic formula: x = (-b ± [tex]\sqrt{b^{2} - 4ac}[/tex] )/(2a)
4x² + x - 9 = 0 ; General form of a quadratic is ax² +bx + c = 0
So a = 4, b = 1, and c = -9
x = -1 ±[tex]\sqrt{1^{2}-4(4)(-9)}[/tex] / 2(4)
x = -1 ± [tex]\sqrt{1 + 144}[/tex] /8
x = -1 ±[tex]\sqrt{145}[/tex] /8
x = (-1 + [tex]\sqrt{145}[/tex])/8 or x = (-1 - [tex]\sqrt{145}[/tex])/8
