1. Section 2.3
Solving for a Variable

2. Objective By following instructions students will be able to:
Rearrange formulas to highlight a quantity of interest, using the same reasoning as in solving an equation.

3. Explore A: Interpreting Parts of an Expression Solve 42=6x
In the formula, V=lwh, the variable h needs to be isolated.

4. Explain 1
The formula for Density is D=m/v. Lead has a very high density of 11,
Plastic foam has a very low density of The formula for density can be rearranged to solve for V or m.
a) A sinker on a fishing line is made of lead and has a volume of What is the mass of the sinker?
b) The design for a life preserver requires .3 kg of plastic foam to provide proper buoyancy. What is the volume of the plastic foam required?

5. Explain 2 The formula for interest is I=prt.
Find the number of years used in the calculation of a $1000 loan at an interest rate of 5% with interest totaling $600.
Determine the interest rate for a $2000 loan that will be paid off in 4 years with interest totaling$640.

6. Your-Turn #1
The formula y=mx+b is the slope-intercept form of the equation of a line. Solve the equation for m.

7. Revisit Objective Did we…
Rearrange formulas to highlight a quantity of interest, using the same reasoning as in solving an equation?

8. Homework
HW:
Page 58 #s 1-19 ODD, 20, 23