Question

Решите уравнение: 2/5=6/x+3; 5/6=15/2x-3; 12:4/5x=20:1/4.

Answer 1

1)$\frac{2}{5} = \frac{6}{x+3} 2(x+3)=6*5 2x+6=30 2x=24 x=12$

2)$\frac{5}{6} = \frac{15}{2x-3} 5(2x-3)=15*6 10x-15=90 10x=105 x=10.5$

3)$12: \frac{4}{5}x = 20: \frac{1}{4} ; 12* \frac{1}{4} = 20* \frac{4}{5}x; 3=16x;x=0.1875$