Sorry, but the answers below are not correct.
Let x = Brad's age
2x is 2 times Brad's age
2x + 7 is Denise's age
x + 11 is Brad's age 11 years from now.
2x + 18 is Denise's age 11 years from now.
3x + 29 = 74 since the sum of their future ages is given.
3x = 45
x = 15 years which is Brad's age by definition.
Denise is 37 years now. In 11 she will be 48 and Brad will be 26. The sum of these two is 74