One number is 9 more than twice another number. if the sum of the numbers is 129 find both numbers

9+x+x = 9 + 2x

129 = 9 + 2x

120 = 2x

x = 60

60 and 69

X and y

x is 9 more than y

x=9+y

if sum is 129

x+y=129

sub 9+y for x

9+y+y=129

9+2y=129

minus 9 both sides

2y=120

divide both sides by 2

y=60

sub back

x=9+y

x=9+60

x=69

the numbers are 60 and 69