Question

Equaçoes de 2 grau A)4x²-12x=0 B)5x²+x=0 C)x²+x=0 D)7x²-x=0 E)2x²=7x F)2x²=8x G)7x²=-14x H)-2x²+10x=0

Answer 1

$a)igualando - 4x^{2}-12x-0=0\\\\delta=12^{2}-4.4.-0=144\\\\x'=\frac{12+12}{8}=3\\\\x''=0\\\\b)igualando-5x^{2}+x-0=0\\\\delta=1\\\\x'=\frac{1+1}{10}=\frac{2}{10}-simplificando - \frac{1}{5}\\\\c)x^{2}+x-0=0\\\\delta=1\\\\x'\frac{1+1}{2}=1\\\\x''=0\\\\d)7x^{2}-x-0=0\\\\delta=1\\\\x'=\frac{1+1}{14}=\frac{2}{14}simplificando\frac{1}{7}\\\\x''=0\\\\e)2x^{2}-7x-0=0\\\\delta=49\\\\x'=\frac{7+7}{4}=3,5\\\\x''=0\\\\f)2x^{2}-8x-0=0\\\\delta=64\\\\x'=\frac{8+8}{4}=4\\\\x''=0\\\g)7x^{2}+14x-0=0$

$delta= 196\\\\x'=zfrac{14+14}{14}=2\\\\x''=0\\\\h)-2x^{2}+10-0=0\\\\delta=100\\\\x'=-5\\\\x''=0$