Question

Me ajudem com essas equacoes
Obgda

Answer 1

3
a) $\frac{-x}{3}$ = 7
    -x = 3*7
    -x = 21  *(-1)
    x = - 21

b)$\frac{x}{4}$ = -3
   x = -3*4
   x = -12

c)$\frac{2x}{5}$ = 4
   2x = 4* 5
   2x = 20
   x = $\frac{20}{2}$
   x = 10

d)$\frac{2x}{3}$ = -10
   2x = -10 * 3
   2x = -30
   x = $\frac{-30}{2}$
   x = -15

e)$\frac{3x}{4}$ = 30
   3x = 30*4
   3x = 120
   x = $\frac{120}{3}$
   x = 40

f)$\frac{2x}{5}$ = -18
  2x = -18 * 5
  2x = -90
  x = $\frac{-90}{2}$
  x = -45

4
a) -x = 9 * (-1)
    x = -9

b)-x = -2 * (-1)
    x = 2

c) -7x = 14
   -x = $\frac{14}{7}$ 
   -x = 2 *(-1)
    x = 2

d)-3x = 10  
 -x =$\frac{10}{3}$ * (-1)
  x = $\frac{-10}{3}$

e)-5 x = -12 *(-1)
    x = $\frac{12}{5}$

f) -4x =8
   -x = $\frac{8}{4}$
  -x = 2 *(-1)
  x = -2

g) -3x = -9 *(-1)
    3x = 9
    x = $\frac{9}{3}$
   x = 3

h)-5x = 15
    -x = $\frac{15}{5}$
    -x = 3 *(-1)
    x = -3

i)-2x = -10 *(-1)
  2x = 10
  x = $\frac{10}{2}$
  x = 5

j)15 = -3x
  -3x = 15 *(-1)
  3x = -15
  x = $\frac{-15}{3}$
  x = -5

k)-40 = -5x *(-1)
   5x = 40
   x = $\frac{40}{5}$
   x = 8

5
a) 6x = 2x + 16
   6x - 2x = 16
   4x = 16
   x = $\frac{16}{4}$
   x = 4

b)2x- 5 = x + 1
  2x - x = 1 + 5
  x = 6

c) 2x + 3 = x + 4
   2x - x = 4 - 3
   x = 1

d) 5x + 7 = 4x +10
   5x - 4x = 10 - 7
   x = 3

e) 4x - 10 = 2x + 2
  4x - 2x = 2 + 12
  2x = 14 
  x = $\frac{14}{2}$
   x = 7

f) 4x -7 = 8x - 2
   4x - 8x = -2 + 7
  -4x = 5 *(-1)
   4x = -5 
   x = $\frac{-5}{4}$

g)2x + 1 = 4x - 7 
  2x - 4x = -7 -1
  -2 x = -8 *(-1)
  2x = 8
  x = $\frac{8}{2}$
  x = 4

h)9x + 9 + 3x = 15
  9x + 3x = 15 - 9
  12x = 6
  x = $\frac{6}{12}$
  x = $\frac{1}{2}$

i)16x -1 = 12x + 3 
  16x - 12x = 3 + 1
  4x = 4
  x = $\frac{4}{4}$
  x = 1

j)3x - 2 = 4x + 9
  3x - 4x = 9 + 2
  -x = 11 * (-1)
  x = -11

k)5x - 3 + x = 2x + 9
  5x - 2x + x = 9 + 3
  4x = 12
  x = $\frac{12}{4}$
  x = 3

l) 17x - 7x = x + 9
  10x - x = 9
  9x = 9
  x = $\frac{9}{9}$
  x = 1

m) x + x - 4 = 17 - 2x + 1
    2x -4 = 18 - 2x
    2x + 2x = 18 + 4
    4x = 22
    x = $\frac{22}{4}$
    x = $\frac{11}{2}$

n) x + 2x + 3 - 5x = 4x - 9
  3x + 3 -5x = 4x - 9
  -2x - 4x = -9 -3
  -6x = -12 *(-1)
  6x = 12
  x = $\frac{12}{6}$
  x = 2