Question

Rezolvati in Z ecuatiile :

a. 9(x - 2) = -63
b. 5(x + 3) = 2(5x - 5)
c. 2(4x + 1) = 2(5x - 7)
d. 2(-x + 5) = -8(3x + 2) + 56
e.1 - 4 * [-5 *(x-2)] = 21
f. 5(x-2) - 7(x + 3) + 35 = 0
g. (x + 3)(x - 7) = 0
h. (-2x + 6)(x + 3) = 0

AJUTOR

Answer 1

a)9x-18=-63 => 9x=-45=> x=5
b)5x+15=10x-10 => -5x=-25 => x=5
c) 8x+2=10x-14 => -2x=-16 =>x=8
d) -2x+10=-24x-16+56 => 22x = 56-26 => x=30/22=15/11
e) 1-4*(-5x+1)=21 => 1+20x -4=21 => 20x=24=> x=20/24=5/6
f)5x-10-7x-21+35=0 =>-2x=4 => x=-2
g) x^2-7x+3x-21=0 => x^2-4x-21=0
 Δ= 16-4*1*(-21) =100 => x1= (4+10)/2=> x1= 7
                                    =>x2= (4-10)/2=> -3
h) -2x^2-6x+6x+18=0 => -2x^2+18=0
-x^2=-9 => x=3