Question 687530
Area = Length * Breadth
A = L * B
And we know that L = B + 1
And that the area is 72

Rewrite the area equation:
72 = L * B
Substitute (B+1) in for L
72 = (B + 1) * B
Simplify
72 = B^2 + B
Set the equation equal to zero

{{{0 = B^2 + B - 72}}}
Now you can use the quadratic equation.
*[invoke quadratic "B", 1, 1, -72]
Note that you can not have a negative value for the answer. So B = 8
Now plug 8 in for B in the L = B + 1 equation
L = 8 + 1
{{{highlight(L = 9)}}}