Вправи: 578 (1-3)

578. Розв’яжіть рівняння:

1) x² – х = 0;

x(x – 1) = 0;

x = 0;

x – 1 = 0;

x = 1.

2) у² + Зу = 0;

y(y + 3) = 0;

y = 0;

y + 3 = 0;

y = –3.

3) 5а² – 4а = 0;

a(5a – 4) = 0;

a = 0;

5a – 4 = 0;

5a = 4;

a = 0,8.

4) d(4d³ – 2d² – 1) = –d;

4d⁴ – 2d³ – d + d = 0;

2d³(2d – 1) = 0;

2d³ = 0;

d = 0;

2d – 1 = 0;

2d = 1;

d = 0,5.

5) 2z(z – 3) + 14z = 19z;

2z² – 6z + 14z – 19z = 0;

2z² – 11z = 0;

z(2z – 11) = 0;

z = 0;

2z – 11 = 0;

2z = 11;

z = 5,5.

6) –х(х – 4) + 3(х – 4) = 0;

(3 – x)(x – 4) = 0;

3 – x = 0;

x = 3;

x – 4 = 0;

x = 4.