Question

Aflati x din proportia:a) x-1 supra 2x+10=1/3;b)x+1supra3x-1=1/2​

Answer 1

Răspuns:

Explicație pas cu pas:

a)  ( x-1)/(2x+10) = 1/3 -> proportie

3 ( x - 1 ) = 2 x + 10 ->  produsul mezilor = produsul extremilor

3 x - 3 = 2 x + 10

3 x - 2 x = 10 + 3

x = 13

Verific:

( 13-1)/2(13+5) = 6/18 = 1/3

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b)  

(x+1)/(3x-1) = 1/2

3 x - 1 = 2(x+1)

3 x - 1 = 2 x + 2

3 x - 2 x = 2 + 1

x = 3

Verific:

(3+1)/(9-1) = 4/8 = 1/2