Let's create expressions and equations to model this situation. Let Anthony's age be a.
"Jim is 3 times as old as his cousin, Anthony." Jim's age is 3a.
"The difference in their age is 18." 3a - a = 18
How old is Jim?
Let's solve the above equation for a to first find Anthony's age.
3a - a = 18
2a = 18
a = 9
Remember, Jim's age is represented by the expression 3a. Substitute Anthony's age, 9, into the expression to find Jim's age.
3a
3(9)
27
Answer:
Jim is 27 years old.
Answer:
Step-by-step explanation:
(a+b)(a-b)
-ab+ab-
Step-by-step explanation:
The way to find missing numbers in equivalent ratios is to multiply the means (the first denominator and the second numerator) and multiply the extremes (the first numerator and the second denominator). It sounds really complicated, but it is quite simple =)
2/5 = x/10
The means in this equivalent ration are 5 and x. The extremes are 2 and 10.
5x = 20
Now solve =)
x = 4
That was pretty simple. Let's move on to the next one. Do exactly the same thing here:
4/10 = 6/x
60 = 4x
15 = x
That was pretty simple, too! Keep going!
6/15 = x/25
15x = 150
x = 10
All of these should be equal, so check them by dividing:
2/5 = 0.4
4/10 = 0.4
6/15 = 0.4
10/25 = 0.4
They all check out, so these are your answers: 2/5, 4/10, 6/15, 10/25
I really hope this helps you =)
Draw the number line then put the numbers on the number line by twos. Fore example, 2-4-6-8-10
