Question

3) Resolva as seguintes equações expressões algébricas
a) 3x - 15 = 8
b) x - 4 = 3
c) 4x + 16 = 8
d) 2x -3 = - 7
e) x + 9 = -1
f) -5x + 28 = 13
g) x - 109 = 5
h) 8x - 39 = -79
i) 10 = x + 9
j) – 3x + 2 = 20
l) 4x + 12 = - 10
m) 7 = x + 8
n) x + 12= 0
o) -3 = 7x + 10

Answer 1

a) 3x=8+15 -> 3x=23 -> x=23/3 -> x=7,6

b)x=3+4 -> x= 7

c) 4x=8-16 -> 4x=-8 -> x=-8/4 -> x=-2

d)2x=-7+3 -> 2x= -4 -> x= -4/2 -> x=-2

e)x=-1+9 -> x=8

f)-5x=13-28 -> -5x= -15 *(-1) -> 5x=15 -> x=15/5 -> x=3

g)x=5+109 -> x= 114

h)8x=-79+39 -> 8x=-40 -> x=-40/8 -> -5

i)10-9=x -> 1=x

j)-3x=20-2 -> -3x=18 -> x=18/-3 -> x=-18/3 -> -6

l)4x=-10-12 -> 4x=-22 -> x=-22/4 -> -5,5

m)7-8=x -> -1=x

n)x=-12

o)7x=-3-10 -> 7x=-13 -> x= -13/7 -> x=-1,85