Question

1- Calcule o valor de x
a) 3/9 = x/3 b) 2/x = 6/24

c) 3/5 = 6/x d) 5/x = 1/0,8

2- Qual o valor de x nas proporções abaixo:
a) 5/2,5 = 10/x b)4/6 = x/x+1

c) 6/x+0,5 = 1/2 d) x-3/x = 4/5

e) 2x-5/x-1 = 1/2 f) 4/3x+2 = 7/5x

me ajudemm pfv

Answer 1

1) a-  3/9 = x/3  é só multiplicar cruzado   9x = 9  x=9/9   x= 1

b- 2/x=6/24   6x=48   x=48/6   x= 8

c- 3/5=6/x  3x=30   x= 30/3  x = 10

d- 5/x= 1/0,8  1x= 4  x=4

2) a- 5/,25= 10/x  5x=25  x=25/5  x=5

b- 4/6=x/x+1   6x= 4*(x+1)   6x= 4x+4   6x-4x= 4    2x =4     x= 2

c- 6/x+0,5= 1/2   1*(x+0,5)=12  x+0,5=12  x= 12-0,5  x= 11,5

d- x-3/x= 4/5   4x= 5*(x-3)  4x= 5x-15  4x-5x= -15   x= -15*(-1)    x= 15

e- 2x-5/x-1= 1/2   1*(x-1)= 2*(2x-5)   x-1= 4x-10  x-4x= -10+1   -3x= -9   x=-9/-3   x= 3

f- 4/3x+2=7/5x  7*(3x+2)=4*(5x)   21x+14=20x   21x-20x = -14    x= -14 * (-1)   x=14