Question

Separate the number 18 into two parts where the product of the part is 77

Answer 1

7 and 11.

Explanation:

so if we say the 2 "parts" are "a" and "b" then we are left with 2 equations

a + b = 18

ab = 77

a = 18 - b

so if ab = 77

b (18 - b) also equals 77

so

-b^2 + 18b = 77

b^2 - 18b + 77 = 0

So b = 7 and 11

You could also solve this via trial and error, but this is a more analytical approach.