Answer: x-1
Step-by-step explanation: if the area of a rectangle is the length multiplied by the width, the width would be the area divided by the length:
A=L*W
W=A/L
substituting the given expressions:

now dividing the polynomials we have that the first term of the quotient is given by:

when multiplying this term by the divisor and substracting the result from the dividend we are left with the following polynomial:

the second term of the quotient is given by:

when multiplying by the divisor and substracting it from the divident the remainder is zero.
so the answer is W=x-1