Question

Determinati numarul x din proportiile :
a) 2 supra 5 = 4 supra x
b) 10 supra x = 5 supra 6
c) x supra 25 = 2 supra 5
d) 3,5 supra 2,5 = x supra 10

Answer 1

a) 2/5 = 4/x
2x = 5 x 4
2x = 20
x = 20/2
x = 10

b) 10/x = 5/6
5x = 6 x 10
5x = 60
x = 60/5
x = 12

c) x/25 = 2/5
5x = 25 x 2
5x = 50
x = 50/5
x = 10

d) 3,5/2,5 = x/10
2,5x = 3,5 x 10
2,5x = 35
x = 35/2,5
x = 350/25
x = 14

Answer 2

a)2/5 = 4/x
x = 5 * 4 : 2
x = 10
b) 10/x = 5/6
x = 10 * 6 : 5
x = 12
c) x/25 = 2/5
x = 25 * 2 : 5
x = 10
d) 3,5/2,5 = x/10
x = 3,5 * 10 : 2,5
x = 14