Monday, April 23, 2007
notes 11.1
Proportion- 2 equal ratios or fractions
a/b = c/d a and d are the extremes and b and c are the means
• If 2 ratios are equal, then their reciprocals are equal too
• If you cross multiply, the products will also be equal
Try: 3/y = 5/8
x/3 = 12/x
Tuesday, April 10, 2007
Practice for Algebra 1 Test Ch 10!!!!!!!!
10.1 Adding and subtracting Polynomials
Find the sum or difference:
1) (-6x3+5x2-3)-(2x3+4x2-3x+1) 2) (6x2-x+3) + (-2x+x2-7)
3) (12x-8x2+6)-(-8x2-3x+4) 4) -(2x3+3x – x +5) – (x3+2x -1)
10.2 Multiplying Polynomials
Multiply:
4) (3t+5)(t-3) 5) (2x+10)( ½ x + 2 ) 6) (3x+4)2
7) (4x2-3x-1)(2x-5) 8) (2x+3)(8-x-3x2)
9) Write a polynomial expression for the area of a rectangle with a length of 2x-1 and a width of 3x+2.
10.4 Solving Polynomial Equations in Factored Form (Using Zero Product Property)
Solve:
10) y=(x-3)(x+2) 11) y=(x-4)(x+2)
12) (2x+1)(3x-2)(x-1)=0 13) (x+5)2=0
10.5 Factoring x2+bx+c
Solve by factoring:
14) x2+11x+10=0 15) x2-17x+60=0 16) x2+6x+9=0
17) x2-2x=24 18) x2-15x= -54 19) –x2-4x=3
10.6 Factoring ax2+bx+c
Solve by factoring :
20) 2x2+x-6=0 21) 9x2+24x=-16 22) 2x2+7x= -3
23) 20x2+23x+6=0 24) 4x2-5x= 6 25) 2x2+3x+9
10.8 Factoring Using the Distributive Property
Solve by factoring:
26) 2x3-10x2+8x=0 27) x4-4x3+x2-4x=0 28) -2x5-2x4+4x3=0
29) 4x2+40x+100 30) 4x2-16x-48 31) 2x2+28x+98
32) The width of a box is 1 cm less than its length. The height of the box is 9cm greater than the length. The box has a volume of 72 cm3. What are the dimensions of the box?
Chapter Wrap Up- Solve the following using any method you choose. Your choices are: Graphing by hand, “Square Rooting”, Quadratic formula, Factoring, **Factoring by Grouping, **Distributive Property + Factoring. You should then choose a SECOND method to check your answer. Lastly, check with the graphing calculator!!!!!!!!! The bold indicates methods that your test will be focusing on. **= you may only use these methods when applicable.
33) x2-60= -11 34) x2-16=0 35) x2-13x= -40
36) (x+9)2 37) 20x2+23x+6 = 0 38) 4x2+12x+9=0
39) 4x2+4x -5=0 40) -2x2+4x+6=0 41) 3x2+14x=5
notice: Ch 10 Test
hw: 4/10
Monday, April 09, 2007
notes 10.7 and 10.8
Difference of 2 squares: a2-b2=(a+b)(a-b)
Ex. 16x2-4 = (4x+2)(4x-2)
Perfect Square Trinomial:
a2+2ab+b2= (a+b)2 Ex: x2+8x+16=(x+4)2
a2-2ab+b2= (a-b)2 Ex: x2-12x+36=(x-6)2
10.8 Factoring Using the Distributive Property
Before you begin to factor a polynomial, it is useful to factor out any common factor among all the terms first.
9x2-15 From this, I can factor out a 3 to get 3(3x2-5)
Once you have factored a polynomial completely, it is called prime
5x2-10x-40 –Factor out a 5 first to get:
5(x2-2x-8) since this it equal to 0, divide both sides by 5 to “get rid” of it
Then factor like normal
Try: 45x4-20x2
5x3+30x2+40x
3x3-15x2-6m+30
ws 10-8 //// puzzle
notes 10.6
1) Write the trinomial in standard form
4x2-21x+5=0
2) Multiply a by c
4•5=20
3) Find factors of ac that will add up to “b”
factors of 20: -1,- 20 -2,- 10 -4,- 5
4)Rewrite the quadratic replacing “bx” with the two new factors
4x2-1x-20x +5=0
4) Split this into two groups
4x2-1x -20x+5
5)”Pull out” common factors
x(4x-1) -5(4x-1)
6) You should now have both binomials in the parentheses identical. If you do not, check your work and adjust your negatives.
7)Whatever is inside the parentheses becomes one factor, the second factor is the terms outside the parentheses
(4x-1)(x-5)
8) FOIL to check
try: 7x2-4x-3
6x2-5x-21
10x2+25x-90
21n2+14n+7=6n+11
ws 10-6
