Question

1) 2n+30=n-15
2) n+90=3n
3) -15x+100=78
4) 9n=-45
5) n+15=38-18
6) 5x+15=-2n+45
7) n+30=-60
8) 9n+15=-90
9) n+18=-3x
10) 4n+20=15

Answer 1

Resposta e explicação passo-a-passo:

1) 2n+30=n-15

  2n -n = -15 - 30

  n = -45

2) n+90=3n

    n - 3n = -90

   -2n = -90

    n = -90÷(-2)

    n = 45

3) -15x+100=78

   -15x = 78 - 100

   -15x = -12

   x = (-12) ÷ (-15)

   x = $\frac{12}{15} = \frac{4}{5}$

4) 9n= - 45

   n = (-45) ÷ 9

   n = -5

5) n+15=38-18

   n = 38 - 18 - 15

   n = 5

6) 5x+15=-2x+45

   5x + 2x = 45 - 15

   7x = 30

   x = $\frac{30}{7}$

7) n+30=-60

   n = -60 - 30

   n = -90

8) 9n+15=-90

   9n = -90 -15

   9n = -105

   n = $-\frac{105}{9} = -\frac{35}{3}$

9) n+18= -3n

   n + 3n = 18

   4n = 18

   n = $\frac{18}{4} =\frac{9}{2}$

10) 4n+20=15

     4n = 15 - 20

     4n = -5

     n = $-\frac{5}{4}$

Espero ter ajudado :)