Question

biết 1+y/9 = 1+2y/7=1+3y/x khi đó x=

Answer 1

1+y/9=1+2y/7=>9(1+2y)=7(1+y)=>9+18y=7+7y=>18y-7y=7-9=>11y=-2=>y=-2/11.

=>1+2y/7=1+2(-2/11)/7=11

=>1+3y/x=11=>1+3(-2/11)/x=11=>(5/11)/x=11=>x=5