Question

rezolva in multimea Z ecuatiile. va rog repede! dau coroana ​

Answer 1

$a)5x = - 10 \\ x = - 10 \div 5 \\ x = - 2 \\ \\ b) - 3x = 3 {}^{2} \\ x = 3 {}^{2} \div - 3 \\ x = - 3 {}^{2 - 1} \\ x = - 3$

$c) - 6x = - 2 \times 3 {}^{3} \\ - 6x = - 2 \times 27\\ - 6x = - 54 \\ x = - 54 \div (- 6 )\\ x = 9$

$d) - 2 {}^{2} \times 7 {}^{3} = 7 {}^{2} \times x \\ x = - 2 {}^{2} \times 7 {}^{3} \div 7 {}^{2} \\ x = - 2 {}^{2} \times {7}^{3 - 2} \\ x = - 4 \times 7 \\ x = - 28$

$e) - 2 {}^{2} \times 3 = - 6x \\ - 4 \times 3 = - 6x \\ - 6x = - 12 \\ x = - 12 \div ( -6) \\ x = 2$

$f)(2 + 3)x = - 15 \\ 5x = - 15 \\ x = - 15 \div 5 \\ x = - 3$

$g)(79 - 84)x = - 10 \\ - 5x = - 10 \\ x = - 10 \div ( - 5) \\ x = 2$

_______EXPLICAȚII_______

Regula semnelor:

LA ÎMPĂRȚIRE:

MINUS : MINUS = PLUS

PLUS : PLUS = PLUS

MINUS : PLUS = MINUS

PLUS : MINUS = MINUS

LA ÎNMULȚIRE:

MINUS • MINUS = PLUS

PLUS • PLUS = PLUS

MINUS • PLUS = MINUS

PLUS • MINUS = MINUS