Question

Determinati numarul necunoscut din fiecare proportie :
4 supra 9 = 3x + 1 supra 2x + 12

Answer 1

4(2x+12)=9(3x+1)
8x+48=27x+9
27x-8x=48-9
19x=39
x=39/19

Answer 2

4/9=3x+1/2x+12
⇒4[2x+12]=9[3x+1]
⇒8x+48=27x+9
⇒27x-8x=48-9
⇒19x=39
⇒x=39/19;