Algebra: Chapter 10-1, p 432
Simplifying Rational Expressions
A rational expression is a quotient of 2 polynomials. A rational expression always indicates division. A rational expression is in simplest form when the numerator and denominator have NO COMMON factors other that 1 or −1.
Factor the numerator and the denominator and see what terms can be cancelled. For example:
`(5x-10)/(5x) = (5(x−2))/(5x) = (5(x−2))/(5x) = (x-2)/x`
and
`(y^2+3y+2)/(y^2-1)=((y+2)(y+1))/((y+1)(y-1))=((y+1)(y+2))/((y+1)(y-1))=(y+2)/(y-1)`
AND, here is a link from purplemath with more examples.
Math-8, Chapter 9-9, p 467
Using Percent Equations
- More whickity-whack divide problems today. Go back to Tuesday’s explanation for these type of problems. Remember, #, % of_ 100 in the box. In the upper left is the # (number)
- In the upper right is the percent (%)
- In the lower left is of_
- In the lower right is ALWAYS 100
Whickity-whack (upper left) * (lower right) = (upper right) * (lower left).
Divide by either 100 or the constant in front of the variable and you have your answer!