Answer:
{1, 2, 3}, {3, 4, 5}
Step-by-step explanation:
Write expressions for three consecutive integers: n, n + 1, n + 2.
Set up an equation for the verbal description: the product (mulitplication) of the two larger integers (the last two) is one less than 7 times the smallest (the first one).
(n + 1)(n + 2) = 7n - 1
Multiply (FOIL) the left side.
n^2 + 3n + 2 = 7n - 1
Subtract 7n and subtract 1 to make the right side 0.
n^2 - 4n + 3 = 0
Factor.
(n - 1)(n - 3) = 0
Set the two factors equal to 0
n - 1 = 0, n - 3 = 0
Solve for n.
n = 1, n = 3
One set of integers begins with 1, so it's {1, 2, 3}.
The other set begins with 3, so it's {3, 4, 5}
