The difference of two numbers is 42. the larger number is three less than six times the smaller number. find the numbers.

X and y are the numbers
x>y

diffference is 42
x-y=42

larger is 3 less than 6 times smaller
x=-3+6y

subsitute -3+6y for x

x-y=42
-3+6y-y=42
-3+5y=42
add3 to both sides
5y=45
divide both sides by 5
y=9

sub back

x=-3+6y
x=-3+6(9)
x=-3+54
x=51

the numbers are 51 and 9