If `x:5/7=7/8:5/4` then `x`

If (x,3)+(2,5)=(7,8) then x is equal to a)2 b)5 c)7 d)9

If (x)/(y)=(6)/(5), then the value of ((6)/(7)-(5x-y)/(5x+y)) is equal to (a) (1)/(7)( b) (2)/(7)(c)(3)/(7) (d) (4)/(7)

If 8(2x-5)-6(3x-7)=1 then x= ?

If 4:5::7:x , then the value of x will be

5x+7=2x-8

If 8(2x-5)-6(3x-7)=10 , then x=?

Show that the lines 3x-4y+5=0,7x-8y+5=0 and 4x+5y=45 are concurrent.