The product of two consecutive even
natural numbers is 120.
Find the numbers.
In problems like this, sometimes you can just guess them.
But if you can't, then do it this way:
x = first even integer
x+2 = second even integer
x(x+2) = 120
x² + 2x = 120
x² + 2x - 120 = 0
a=1, b=2, c=-120
Using the +
So one solution is
x = 10 = first even integer
x+2 = 10+2 = 12 = second even integer
Using the -
So another solution is
x = -12 = first even integer
x+2 = -12+2 = -10 = second even integer
Edwin
