Question

розкласти на множники:
9d²+6d+1
()*()

Answer 1

$9d^2+6d+1=3^2d^2+2*3d*1+1^2=(3d)^2+2*3d*1+1^2=(3d+1)^2$

Answer 2

$9 {d}^{2} + 6d + 1 = 0 \\ d = {b}^{2} - 4ac = {6}^{2} - 4 \times 9 \times 1 = 36 - 36 = 0 \\ x = \frac{ - b}{2a} = \frac{ - 6}{2 \times 9} = \frac{ - 6}{18} = - \frac{1}{3}$

Получается

$9 {d}^{2} + 6d + 1 = 9 \times {(d + \frac{1}{3}) }^{2}$