Question

Two numbers that multiply to equal 405 but add to equal 42

Answer 1

x*y=405
x+y=42
y=405/x
x+405/x=42
x^2+405=42x
x^2-42x+405=0
(x-27)(x-15)=0
x=27
x=15

Answer 2

27 and 15 add up to 42 and when multiplies they have a sum of 405

simply do trial and error for this type of question, try using factors of the number to find out what can be used to equal the number