Question

Daca a/b=2/3aflati3a-4b/5a-2b

Answer 1

a/b = 2/3 => a= 2k , b= 3k

3a-4b = 3*2k - 4*3k = 6k - 12k = -6k

5a - 2b= 5*2k - 2*3k = 10k - 6k = 4k

-6k / 4k = -6 / 4 = -3 / 2

Answer 2

$\it \dfrac{a}{b} = \dfrac{2}{3} \Longrightarrow b = \dfrac{3a}{2} \ \ \ \ (*)$

$\it\dfrac{3a-4b}{5a-2b} \ \stackrel{(*)}= \dfrac{3a-4\cdot \dfrac{3a}{2}}{5a-2\cdot\dfrac{3a}{2} } = \dfrac{3a-6a}{5a-3a} = \dfrac{-3a}{2a} = \dfrac{-3}{2} = -1,5$