Question

determinati numarul natural x stiind ca urmatoarele fractii sunt echivalente: a) $\frac{2x+5}{x+3}$ si $\frac{9}{5}$ b)$\frac{3x+2}{5x+6}$ si $\frac{11}{21}$.Va rog ajutatima

Answer 1

(2x+5)/(x+3)=9/5
5(2x+5)=9(x+3)
10x+25=9x+27
10x-9x=27-25
x=2

b)(3x+2) /(5x+6)=11/21
21(3x+2)=11(5x+6)
63x+42=55x+66
63x-55x=66-42
8x=24
x=3