Question

De rezolvat ecuațiile:
1) (x-3) (x+7)=0
2) x² - 36=0
3) |7x|=56
H) |3x+2|=11

Answer 1

Răspuns:

1) x = 3; x = -7

2) x = +/- 6

3) x = +/- 8

H) x = 3; x = -13/3

Answer 2

a)

$\left(x-3\right)\left(x+7\right)=0$

$x-3=0$

$x-3+3=0+3$

$x=3$

$x=3,\:x=-7$

b)

$x^2-36=0$

$x^2-36+36=0+36$

$=\sqrt{36},\:x=-\sqrt{36}$

$\sqrt{36}=6$

$-\sqrt{36}=-6$

$x=6,\:x=-6$

c) $\left|7x\right|=56$

$7x=-56\quad \mathrm{sau}\quad \:7x=56$

$7x=-56\quad :\quad x=-8$

$7x=56\quad :\quad x=8$

$x=-8\quad \mathrm{sau}\quad \:x=8$

d) $\left|3x+2\right|=11$

$3x+2=-11\quad \mathrm{sau}\quad \:3x+2=11$

$x+2=-11\quad :\quad x=-\frac{13}{3}$

$3x+2=11\quad :\quad x=3$

$x=-\frac{13}{3}\quad \mathrm{sau}\quad \:x=3$

Sper că te-am ajutat!

Succes!