Use proportions and use letters for unknown measurements
http://goblues.org/faculty/grantm/files/2015/12/Practice-Test-3.7-Solutions.pdf
I think it's question number three. Sorry if the link dosen't work.
Answer:
Fred is 28 yrs old. Nathalie is 12yrs old
Step-by-step explanation:
Let Nathalie's age be x
Let Fred's age be a
x+a=40 yrs•••••1
4x+a=76yrs•••••2
a=40-x
Substitute a for 40-x in equation (2)
4x+40-x=76
3x=76-40
3x=36
x=12
a=40-12
a=28
Answer:
six hundred sixteen thousand eight hundred forty five
Step-by-step explanation:
