Answer
$d=81$
Work Step by Step
In order to solve this algebraic expression, we must isolate the variable. A variable is the letter in the problem (for instance, in the equation 2x=10, x is the variable).
In the expression 36=4/9d, d is being multiplied by a fraction, which we must cancel out. In order to cancel out a fraction being multiplied by a variable, we multiply both sides of the equation by the reciprocal of the fraction, which is the fraction flipped upside down. (For instance, the reciprocal of ⅖ is 5/2).
Thus, we multiply both sides of the equation by 9/4 to obtain that $d=81$.
We plug 81 in for d and confirm that our answer is, indeed, correct.
