Explanation:
y÷15 or y/15 = 6
let's ignore the remainder for a moment.
y/15 = 6
y = 6×15 = 90
now, what does "remainder" mean ?
it means after a clean division there is a result, and there is still this additional remainder left.
the actual result of
a/b is
a/b = c + remainder/b
where c is an integer, and remainder is also an integer.
so, a = b×c + b×remainder/b = b×c + remainder
therefore,
y = 6×15 + 8 = 98
to check
98/15 = 6 remainder 8
so, it is correct
314÷y = 18 remainder 8
314 = 18y + 8
306 = 18y
y = 306/18 = 17
check
314 / 17 = 18 remainder 8
so, it is correct.