Question

Resolva as equações

a) 3.x=15

b) 2.x=14

c) 4x= -12

d) 4x= -21

e) 13.x=13

f) -5x= -12

g) x/4= -3

h) 2.x/5=4

i) 2.x/3=10

j) 2.x/3 = 18

k) 3x/4 = 30

Answer 1

$a) \: 3x = 15 \\ \: \: \: \: x = \frac{15}{3} \\ x = 5 \\ \\ b) \\ x = \frac{14}{2} \\ x = 7 \\ \\ c) \: 4x = - 12 \\ x = \frac{ - 12}{4} \\ x = - 3 \\ \\ d) \: 4x = - 21 \\ x = \frac{ - 21}{4} \\ \\ e)13x = 13 \\ x = \frac{13}{13} \\ x = 1 \\ \\ f) - 5x = - 12 \\ x = \frac{ - 12}{ - 5 } \\ \\ g) \frac{x}{4} = - 3 \\ x = - 3 .4 \\ x = - 12 \\ \\ h) \frac{2x}{5} = 4 \\ 2x = 4.5 \\ 2x = 20 \\ x = \frac{20}{2} \\ x = 10 \\ \\ i) \frac{2x}{3} = 10 \\ 2x = 10 .3 \\ 2x = 30 \\ x = \frac{30}{2 } \\ x = 15 \\ \\ j) \frac{2x}{3} = 18 \\ 2x = 18 .3 \\ 2x = 54 \\ x = \frac{54}{2} \\ x = 27 \\ \\ k) \frac{3x}{4} = 30 \\ 3x = 30.4 \\ 3x = 120 \\ x = \frac{120}{3} \\ x = 40$
espero ter ajudado....