Answer:
The numbers are 8 and 9.
Step-by-step explanation:
x(x+1) = 72 Distribute
x^2 + x = 72 Plug in values for x until one of them works
8^2 + 8 = 72 In this case, 8 is the number that works
64 + 8 = 72 Add
72 = 72
Now plug this into the original equation
8(8+1) = 72 Add
8(9) = 72 Multiply
72 = 72
