9.2-Direct, Inverse, and Joint
This section is on the relationships in equations with variables and numbers. Within this section you will learn how to read an equation, plug in the numbers and find a solution. Here are three words related to these equations you will need to know for the problems.
Jointly- Y=kXZ (multiply more than two)
Inversely- Y=k/X (Divide)
Directly- Y=kX (multiply)
*Little k= constant of proportionality
There
are 5 steps to solving these equations. (These are from Ms. Blackwell's
Head)
1. Write Equation
2. Fill-in
3. Find k
4."Equation"
5. Solve
These equations always have two parts...first solving for the variable in the equation and then plugging in your answer to a new equation.
Let's try some!!!!!!!!!!!!!
Directions: Name these equations as direct, inverse, or joint.
1.Y=5x6 2. Y=8xz 3. Y=x/2
Directions: Solve this equation.
1. If Y varies directly as X and Y=12 when X=6, find y when X=20
You can check your answers below.
1.Direct 2.Jointly 3.Inversely
1.k= 2 and y=10