1. 2-8 Solving for a Specific Variable
Solve for x.
ax – b = c
+ b +b Add b to both sides
ax = c + b Simplify
ax = c + b
a a Divide both sides by a
x = c + b
a Simplify

2. Solve for x. 15x + 1 = y -1 -1 Subtract 1 from both sides
15x = y – 1 Simplify
15x = y – 1
Divide both sides by 15
x = y – 1
15 Simplify

3. Try These 1) Solve for b. 5b + 12c = 9 2) Solve for x. 7x – 2z = 4 – y
1) Answer: b = 9 – 12c 5
2) Answer: x = 4 – y + 2z 7

4. Formulas
A car’s fuel economy E (miles per gallon) is given by the formula E = m/g, where m is the number of miles driven and g is the number of gallons used.
A. Solve the formula for m.
B. If Claudia’s car has an average fuel consumption of 30 miles per gallon and she used 9.5 gallons, how far did she drive?

5. The formula for the volume of a cylinder is V = r2h, where r is the radius of the cylinder and h is the height.
Solve the formula for h.
What is the height of a cylindrical swimming pool that has a radius of 12 feet and a volume of 1810 cubic feet?

6. Try These – p. 119 1-7 odd 1. x = b/9 3. y = 3c – a 5. h = 2A/b
min
Homework #17 p even, 39-40