Question

Решите уравнение: 1)7x^2=21 2)6x^2+x=0. 3)x^2= - 8x. 4)x^2+8x+16=0​

Answer 1

1)7x² = 21|:7

x² = 3

|x| = ✓3

x = ±✓3

2)6x²+x = 0

x(6x+1) = 0

[x = 0

[6x+1 = 0

6x = -1|:6

x = -1/6

3)x² = -8x

x²+8x = 0

x(x+8) = 0

[x = 0

[x+8 = 0

x = -8

4)x²+8x+16 = 0

(x+4)² = 0

x+4 = 0

x = -4