Resolva as questões a)7y+5-y+8=31 b)5.(3-2a)55 c)27=3.(x+3) d...

a - 7y + 5 - y + 8 = 31

7y - y = 31 - 5 - 8

6y = 31 - 13

6y = 18    y = 18/6     y = 3

b ) 5( 3 - 2a) = 55

   15 - 10a = 55

 10a = 55 - 15

 10a = 40      a = 40/10      a = 4

c)  27=3.(x+3)

   27 = 3x + 9

3x = 27 - 9       3x = 18     x= 18/3  x = 6

D)16x+2.(7x+8)-9=67

16x + 14x + 16 - 9 = 67

30x = 67 - 16 + 9

30x = 60       x = 60/30   x=2

E)6.(4z+2)+7.(-5z+3) = 66

24z + 12 -35z +21 = 66

-11z = 66 - 33     z = 33/-11    z = - 3

F)12+(3x+6).(-7)-5=70

12 - 21x - 42 -5 = 70

-21x = 70 - 12 +42 +5

- 21x = 105     x = 105/-21    x= -5