727° Вправа 727Алгебра 8 клас Тарасенкова 2025 · § 17 · стор. 215

727. Зведіть рівняння до вигляду ax² + bx + c = 0:

1) ${\displaystyle (x-4)(x+1)=}$${\displaystyle x-7}$;

${\displaystyle x^2+x-4x-4-x+7=}$${\displaystyle 0}$;

${\displaystyle x^2-4x+3=}$${\displaystyle 0}$;

2) ${\displaystyle 7x^2-3=}$${\displaystyle x(x-11)+1}$;

${\displaystyle 7x^2-3=}$${\displaystyle x^2-11x+1}$;

${\displaystyle 7x^2-3-x^2+11x-1=}$${\displaystyle 0}$;

${\displaystyle 6x^2+11x-4=}$${\displaystyle 0}$;

3) ${\displaystyle 2(3x-1)=}$${\displaystyle {(3x-1)}^2-1}$;

${\displaystyle 6x-2=}$${\displaystyle 9x^2-6x+1-1}$;

${\displaystyle 6x-2-9x^2+6x=}$${\displaystyle 0}$;

${\displaystyle -9x^2+12x-2=}$${\displaystyle 0}$, або ${\displaystyle 9x^2-12x+2=}$${\displaystyle 0}$;

4) ${\displaystyle 4(x-2)(x+2)+5=}$${\displaystyle 7(x-2)}$;

${\displaystyle 4(x^2-4)+5=}$${\displaystyle 7x-14}$;

${\displaystyle 4x^2-16+5-7x+14=}$${\displaystyle 0}$;

${\displaystyle 4x^2-7x+3=}$${\displaystyle 0}$.