Answer:
Step-by-step explanation:
Let x = the age of the youngest child
Let x + 1 = the age of the middle child
Let x + 2 = the age of the oldest child
x + x + 1 + x + 2 = 39
3x + 3 = 39
3x = 36
x = 12 years
How many times do 15 minutes fit into one hour? 4 times: 4*15=60 mins.
So that means that 4 times per hour 10 flights appear, and in total 4*10=40 planes arrive over one hour!
Use KMF (Keep multiply flip)
keep the first fraction as it is
change sign to multiplication
flip numerator and denominator of last fraction
then finish