Question

By what number is (a+bx) to be divided in order to get ‘a’ as the quotient and ‘b’ as the reminder?

Answer 1

divident = divisor×quotient + remainder

Let "m" is the divisor
devident = a + bx
quotient = a
reminder = b

That is,
a + bx = m × a + b
ma = a + bx - b
m = ( a + bx - b )/a