Lilolexiid
Answered

How do you do [tex] x^{2} -9x=15[/tex]

Sagot :

[tex]x^2-9x=15\\x^2-9x-15=0\\a=1;\ b=-9;\ c=-15\\\Delta=b^2-4ac\to\Delta=(-9)^2-4(1)(-15)=81+60=141\\\\x=\frac{-b\pm\sqrt\Delta}{2a}\to x=\frac{9\pm\sqrt{141}}{2}[/tex]