Question

сейчас надо, срочно​

Answer 1

1)

$displaystyle tt 5x^2-14x-3=0\displaystyle tt D=(-14)^2-4cdot5cdot(-3)=196+60=256\displaystyle tt sqrt{D}=sqrt{256}=16\\ displaystyle tt bold{x_1}=frac{14+16}{2cdot5}=frac{30}{10}=3\\ displaystyle tt bold{x_2}=frac{14-16}{2cdot5}=frac{-2}{10}=-frac{1}{5}=-0,2$

2)

$displaystyle tt 3x^2+24x=0\displaystyle tt 3x(x+8)=0\\ displaystyle tt 3x=0\displaystyle tt bold{x_1=0}\\ displaystyle tt x+8=0\displaystyle tt bold{x_2=-8}$

3)

$displaystyle tt 2x^2-32=0\displaystyle tt 2(x^2-16)=0\\ displaystyle tt x^2-16=0\displaystyle tt x^2=16\displaystyle tt x=sqrt{16}\displaystyle tt bold{x_1}=4\displaystyle tt x=-sqrt{16}\displaystyle tt bold{x_2=-4}$