+948 Seven years ago, Grogg's dad was 9 times as old as Grogg. Four years ago, Grogg's dad was 5 times as old as Grogg. How old is Grogg's dad currently?
+1279 Seven years ago, Grogg's dad was 9 times as old as Grogg. Four years ago, Grogg's dad was 5 times as old as Grogg. How old is Grogg's dad currently?
(D – 7) = 9 • (G – 7)
D = 9G – 63 + 7 = 9G – 56
(D – 4) = 5 • (G – 4)
D = 5G – 20 + 4 = 5G – 16
9G – 56 = 5G – 16
4G = 40 ==>> Grogg's current age is 10
D = 9G – 56 = (9)(10) – 56
D = 90 – 56 ==>> Dad's current age is 34
check answer
(34 – 7) =? 9 • (10 – 7) ==> 27 = 27 True
(34 – 4) =? 5 • (10 – 4) ==> 30 = 30 True
.
