Chapter 2,
- Solving Word Problems
- Read the problem carefully.
- Draw a picture (if you can) illustrating the problem.
- Identify unknown quantities you're being asked to find.
- Choose a variable to represent one quantity.
- Write down, in words, what the variable (you chose in 4) represents.
- Represent other quantities to be found in terms of the variable (you chose in 4).
- Write the word problem as an equation (hard step--takes practice).
- Solve the equation for the unknown quantity.
- Answer the question asked in the word problem.
- Check your solution in the original word problem.
- Some Common Formulas
Formula Use A = r2 Area of a circle.
r is the radiusC = 2r Circumference of a circle.
r is the radiusA = LW Area of a rectangle.
L is length, W is widthP = 2L + 2W Perimeter of a rectangle.
L is length, W is widthA = 1
2BH Area of a triangle.
B is base length, H is heighta2 + b2 = c2 Pythagoean theorem for a right triangle.
a, b lengths of legs
c length of hypotenuseA = Prt Simple interest.
A is interest earned,
P is the principal,
r is the interest rate (decimal),
t is timeA = P(1 + r
n) 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 yearsA = Rt Rates.
A is amount, R is rate, t is timed = vt Distance and speed.
d is distance, v is speed, t is timeC = 5
9(F - 32) Temperature conversion.
F is degrees Fahrenheit
C is degrees Centigrade
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