Define a∗b as 2a−b2. If a∗5=9, what is the value of a?
a * b = 2a - b^2
So
a * b = a * 5 = 9
So...this implies that b = 5
So we have
2a - b^2 = 9
2a - (5)^2 = 9
2a - 25 = 9 add 25 to both sides
2a = 34 divide both sides by 2
a = 17
