Question

X^2-5x-8=0 find the roots (zeros)

Answer 1

`x_1=(5-√(57))/(2)\ ,\quad x_2=(5+√(57))/(2)`

Explanation:

`x^2-5x-8=0\\\\a=1\,,\ b=-5\,,\ c=-8\\\\x=(-b\pm√(b^2-4ac))/(2a)\\\\x=(-(-5)\pm√((-5)^2-4\cdot1\cdot(-8)))/(2\cdot1)=(5\pm√(25+32))/(2)=(5\pm√(57))/(2)`