Решите уравнение. а)-20х=1,6х^2 б)х^-11х+30=0 в)3х^+7х-40=0
1)-20x=8/5x^2 -100x=8x^2 100x-8x^2=0 x(25+2x)=0 x=0 x=-25/2=12,5 2)x^2-11x+30=0 D=-b^2-4ac x= x=6 x=5[/tex] 3)3x^2+7x-40=0 x=
![\frac{-(-11)+- \sqrt{(-11)^2-4*1*30} }{2}[tex] \\ \\](https://tex.z-dn.net/?f=+%5Cfrac%7B-%28-11%29%2B-+%5Csqrt%7B%28-11%29%5E2-4%2A1%2A30%7D++%7D%7B2%7D%5Btex%5D+%5C%5C++%5C%5C+ "\frac{-(-11)+- \sqrt{(-11)^2-4*1*30} }{2}[tex] \\ \\")
x=6
x=5[/tex]
