Question

Giai phuong trinh:

a, \(\left(x+2\right)^2-\left(x-2\right)^3=12x\left(x-1\right)-8\)

b, \(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+116}{4}=0\)

Answer 1

<=>\(\left(x+2\right)^2-\left(x-2\right)^3=-\left(x-6\right)\left(x^2-x+2\right)\)

=>\(12x\left(x-1\right)-8=4\left(3x^2-3x-2\right)\)

=>\(-\left(x-6\right)\left(x^2-x+2\right)=4\left(3x^2-3x-2\right)\)

=>x=-5;-2 hoặc 2

Answer 2

<=>\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+116}{4}=\frac{1894289\left(x+100\right)}{6370665}\)

=>\(\frac{1894289\left(x+100\right)}{6370665}=0\)(rút gọn)

=>\(\frac{1894289x}{6370665}+\frac{37885780}{1274133}=0\)

=>\(\frac{1894289\left(x+100\right)}{6370665}=0\)(giải PT này )

=>x=-100