Question

Com a equação polinomial de 1 grau. Encontre as incógnitas (×). Todas as questões devem conter o desenvolvimento

×+30=40?
30-20+2×=10?
3×10=2×+28?
20x-30=40+30-20?
5×+45-89=90+41?
10×-20=40+50?
20-80+2×-10?
19+2-13=10-20?
10×-12=+18-20?
13×-23-45=-7×+12?​

Answer 1

Olá!

a) x+30 = 40

   x = 40 - 30

   x = 10

b) 30 - 20 + 2x = 10

   10 + 2x = 10

   2x = 10 - 10

   2x = 0

   x = 2

c) 3x + 10 = 2x + 28

   3x - 2x = 28 - 10

   x = 18

d) 20x - 30 = 40 + 30 - 20

   20x - 30 = 50

   20x = 50 + 30

   20x = 80

        x = $\frac{80}{20}$

        x = 4

e) 5x + 55 - 89 = 90 + 41

   5x - 34 = 131

   5x = 131 + 34

   5x = 165

     x = $\frac{165}{5}$

     x = 33

f) 10x - 20 = 40 + 50

  10x - 20 = 90

  10x = 90 + 20

  10x = 110

     x = $\frac{110}{10}$

     x = 11

g) 20 - 80 + 2x - 10

   -60 + 2x - 10

   -70 + 2x

   2x = 70

     x = $\frac{70}{2}$

     x = 35

h) 19 + 2 - 13 = 10 - 20

   21 - 13 = -10

   8 = -10

   -10 + 8

   -2

i) 10x - 12 = 18 - 20

  10x - 12 = -2

  10x = -2 + 12

  10x = 10

      x = $\frac{10}{10}$

      x = 1

j) 13x - 23 - 45 = -7x + 12

  13x + 7x = 23 + 45 + 12

  20x = 80

      x = $\frac{80}{20}$

      x = 4