Question

Which are the solutions to the quadratic equation x^2=9x+6

Answer 1

I will use a quadratic formula:


`x^2=9x+6\ \ \ \ |-9x-6\\\\x^2-9x-6=0\\\\a=1;\ b=-9;\ c=-6\\\\b^2-4ac=(-9)^2-4\cdot1\cdot(-6)=81+24=105\\\\√(b^2-4ac)=√(105)\\\\x_1=(-b-√(b^2-4ac))/(2a);\ x_2=(-b+√(b^2-4ac))/(2a)\\\\x_1=(-(-9)-√(105))/(2\cdot1)=(9-√(105))/(2)\\\\x_2=(-(-9)+√(105))/(2\cdot1)=(9+√(105))/(2)`