Class Work 1/29/08

Algebra 2C (1-28-08)
Mileposts

These problems are Milepost problems. Milepost problems are composed of a set of skills that all students should be comfortable with using. From this point on, you will be expected to solve these types of problems. If you need help solving any of these problems then you need more practice. During the next class, inform me of what skill you do not feel comfortable executing. I will work with and then give you a sheet of problems, which will allow you to Practice those skills.

Skill #1

Find the x- and y- intercepts for the graph of: y = x² + 4x -17

X intercept is (-6.5,0) and (2.5, 0) (Parabola) Not true, someone needs to use the quadratic formula
Y intercept is (0,-17)

Skill #2

Solve the system at the right by graphing each line and finding their intersection, then solve the system algebraically to check.

x+(1/3x+1)=5
3/3x+(1/3x+1)=5
4/3x+1=5
-1 -1
4/3x=4
3*(4/3x)=(4)*3
4x=12
(4x=12)/4
x=3
y=1/3(3)+1
y=2

ok

Skill #3

Simplify each expression.

a) (2x²y)⁴
16x⁶y^{4 Not true}

= -3y³/36 = -y³/12 bueno

= 16x⁶y⁴ / 3x y⁵ = 16x⁵ / 3y not true

d) 5(5xy)²(x³y)
(125x²y²) (x³y)= not true
125x⁵y⁴

Skill #4

Solve this system of linear equations in two variables.

5x - 4y = 7
2y+ 6x = 22

Skill #5

Multiply and Simplify

a) (x+1) (2x²-3) Bueno

2x³-3x+2x²-3

b) (x+1)(2x-3)²
(x+1)(2x-3)(2x-3)
4x²-6x-6x+9
(x+1)(4x²-12x+9)
4x³-12x²+9x+4x²-12x+9
4x³-8x²-3x+9 good

c) 2(x+3)²
(2X+6)(2x+6)
4x²+12x+12x+36
4x²+24x+36


Revised: Correct way
2(x+3)(x+3)
x²+3x+3x+9
2(x²+6x+9)

2x²+12x+18


d) (x+1)(2x-3)²
(x+1)(2x-3)(2x-3)
4x²-6x-6x+9
(x+1)(4x²-6x-6x+9)
4x³-6x²-6x²+9x+4x²-6x-6x+9
4x³-8x²-3x+9 good


Skill #6

Factor each expression
a) 4x²-1
(2x-1)(2x+1) yes

b) 4x²+4x+1
(2x+1)(2x+1) yup

c) 2y²+5y+2
(2y+1) (y+2) si


d) 3m²-5m-2
(3m+1) (m-2) por supuesto

Skill #7

Rewrite the following equations so that you could enter them into the graphing calculator.

a) x-3(y+2)=6
x-3y-6=6
x-3y=12
-3y=12-x
-3y/-3=12-x/-3
y=-4+x/3 yup

6x-1 =5 Not finished
y

(㊦y-4)²=(x+1)²
y-4=(x-1)²
+4 +4
y=(x+1)²+4

Not done

e) Find the x- and y-intercepts for each of the graphs created by the calculator forms of the equations in parts (a) through (d). Not done