Răspuns:
Explicație pas cu pas:
a)
x - 2 = -63 : 9 = -7
x = -7 + 2 = -5
b)
5x + 15 = 10x - 10
10x - 5x = 15 + 10
5x = 25
x = 25 : 5 = 5
c)
8x + 2 = 10x - 14
10x - 8x = 14 + 2
2x = 16
x = 16 : 2 = 8
d)
-2x + 10 = -24x - 16 + 56
24x - 2x = 56 - 16 - 10
22x = 30
x = 30/22 = 15/11
e)
1 - 4*(-5x + 10) = 21
1 + 20x - 40 = 21
20x = 21 - 1 + 40 = 60
x = 60 : 20 = 3
f)
5x - 10 - 7x - 21 + 35 = 0
-2x + 4 = 0
2x = 4
x = 4 : 2 = 2
g)
x + 3 = 0 ⇒ x = -3
x - 7 = 0 ⇒ x = 7
h)
-2x + 6 = 0
2x = 6 ⇒ x = 6 : 2 = 3
a) 9(x-2)=-63
9x-18=-63
9x=-63+18
9x=-45
x=-45:9
x=-5
b) 5(x+3)=2(5x-5)
5x+15=10x-10
5x-10x=-10-15
-5x=-25 /·(-1)
x=5
c) 2(4x+1)=2(5x-7)
8x+2=10x-14
8x-10x=-14-2
-2x=-16 /·(-1)
x=8
d) 2(-x+5)=-8(3x+2)+56
-2x+10=-24x-16+56
-2x+24x=40-10
22x=30 ⇔ x=30/22 ⇒ x=15/11
e) 1-4·[-5·(x-2)]=21
1-4·(-5x+10)=21
1+20x-40=21
20x-40=20
20x=20+40
20x=60 ⇒ x=3
f) 5(x-2)-7(x+3)+35=0
5x-10-7x-21+35=0
-2x+4=0
-2x=-4 /·(-1) ⇒ x=2
g) (x+3)(x-7)=0
x+3=0 ⇒ x=-3
x-7=0 ⇒ x=7
h) (-2x+6)(x+3)=0
-2x²-6x+6x+18=0
-2x²+18=0 /:(-2)
x²-9=0
x²=9 ⇒ x=±3
