A man is 4-times as old as her daughter. After 16-years, he will be twice as old as his daughter. Find the daughter’s age.
x = daughter's age now
4x = man's age now {man is 4 times as old as daughter}
x + 16 = daughter in 16 years
4x + 16 = man in 16 years
4x + 16 = 2(x + 16) {after 16 years, he will be twice as old as her}
4x + 16 = 2x + 32 {used distributive property}
4x = 2x + 16 {subtracted 16 from both sides}
2x = 16 {subtracted 2x from both sides}
x = 8 {divided both sides by 2}
4x = 32 {substituted 8, in for x, into 4x}
x = 8 {divided both sides by 4}
daughter is 8
- Algebra House
4x = man's age now {man is 4 times as old as daughter}
x + 16 = daughter in 16 years
4x + 16 = man in 16 years
4x + 16 = 2(x + 16) {after 16 years, he will be twice as old as her}
4x + 16 = 2x + 32 {used distributive property}
4x = 2x + 16 {subtracted 16 from both sides}
2x = 16 {subtracted 2x from both sides}
x = 8 {divided both sides by 2}
4x = 32 {substituted 8, in for x, into 4x}
x = 8 {divided both sides by 4}
daughter is 8
- Algebra House