INCÓGNITA A)21×-17=109 B) 73×+100=53× C)1,7+2,5×=4,2 D)23×-22=19×+6 E)12×-16=21+10× F)1,9×-3,6=×-10,8 G) 10(×+1)-5(×-2)=70 H)5(×+2)-13=2(3×-1) I)7(2+×)=5(×-1,2)+35 J)3(×-1)-2(×-1)= -(×+5)
Soluções para a tarefa
Explicação passo-a-passo:
a)
21x - 17 = 109
21x = 109 + 17
21x = 126
x = 126/21
x = 6
b)
73x + 100 = 53x
73x - 53x = -100
20x = -100
x = -100/20
x = -5
c)
1,7 + 2,5x = 4,2
2,5x = 4,2 - 1,7
2,5x = 2,5
x = 2,5/2,5
x = 1
d)
23x - 22 = 19x + 6
23x - 19x = 6 + 22
4x = 28
x = 28/4
x = 7
e)
12x - 16 = 21 + 10x
12x - 10x = 21 + 16
2x = 37
x = 37/2
f)
1,9x - 3,6 = x - 10,8
1,9x - x = -10,8 + 3,6
0,9x = -7,2
x = -7,2/0,9
x = -72/9
x = -8
g)
10.(x + 1) - 5.(x - 2) = 70
10x + 10 - 5x + 10 = 70
5x + 20 = 70
5x = 70 - 20
5x = 50
x = 50/5
x = 10
h)
5.(x + 2) - 13 = 2.(3x - 1)
5x + 10 - 13 = 6x - 2
5x - 3 = 6x - 2
5x - 6x = -2 + 3
-x = 1 .(-1)
x = -1
i)
7.(2 + x) = 5.(x - 1,2) + 35
14 + 7x = 5x - 6 + 35
7x + 14 = 5x + 29
7x - 5x = 29 - 14
2x = 15
x = 15/2
j)
3.(x - 1) - 2.(x - 1) = -(x + 5)
3x - 3 - 2x + 2 = -x - 5
x - 1 = -x - 5
x + x = -5 + 1
2x = -4
x = -4/2
x = -2