tgt

## Sunday, 24 March 2013

### Intermediate Algebra chapter 2 part 3

Word Problems
Chapter 2,
Solving Word Problems
2. Draw a picture (if you can) illustrating the problem.
3. Identify unknown quantities you're being asked to find.
4. Choose a variable to represent one quantity.
5. Write down, in words, what the variable (you chose in 4) represents.
6. Represent other quantities to be found in terms of the variable (you chose in 4).
7. Write the word problem as an equation (hard step--takes practice).
8. Solve the equation for the unknown quantity.
10. Check your solution in the original word problem.
Some Common Formulas
FormulaUse
A = r2Area of a circle.
C = 2rCircumference of a circle.
A = LWArea of a rectangle.
L is length, W is width
P = 2L + 2WPerimeter of a rectangle.
L is length, W is width
 A = 12 BH
Area of a triangle.
B is base length, H is height
a2 + b2 = c2Pythagoean theorem for a right triangle.
a, b lengths of legs
c length of hypotenuse
A = PrtSimple interest.
A is interest earned,
P is the principal,
r is the interest rate (decimal),
t is time
 A = P(1 + rn ) nt
Compound interest.
A is interest earned,
P is principal,
r is interest rate (decimal),
n is number of times interest is paid per year,
t is time in years
A = RtRates.
A is amount, R is rate, t is time
d = vtDistance and speed.
d is distance, v is speed, t is time
 C = 59 (F - 32)
Temperature conversion.
F is degrees Fahrenheit