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.
To find the answer, use
, and then use the equation
To find it's half life.
Answer:
1.6 < x < 9.6
Step-by-step explanation:
The smallest the third side can be is greater than the difference of the other two sides
x > 5.6 -4
x > 1.6
The largest the third side can be is less than the sum of the other two sides
x < 5.6 +4
x < 9.6
1.6 < x < 9.6
Often with regrouping of 2 numbers then counting them once all together