Thursday, April 3, 2014

There was 52 people at a football game. Three times as many children as adults. Find how many children and adults went to the game by using a system.

c=3a
a+c=52 

so 4a=52
a=13 
c=3a=39

39 children

find a rectangular form of the equation r=5cos(t)

r=5cost
r%2Ar=5rcost
x%5E2%2By%5E2=5x

The length of a football field is 180 feet more than its width. If the perimeter of the field is 1,060 feet, find the length of the field.

P=2(l+w)
l=180+w 

1060=2(180+w+w) 
2w+180=1060/2
2w=530-180
w=175

Without making a drawing, how can you tell that the graph of y = x - 30 passes through three (3) quadrants?

When x%3C0 both x and y are negative (quad III).


When 0+%3C+x+%3C+30 x is positive and y is negative (quad IV). 

When x%3E30 they are both positive (quad I))).

A math test has 25 problems. Some problems are worth 2 points and some are worth 3 points and the total for the test is 66. How many 2 points and 3 points promblems are there.

x-->2pt questions
y-->3pt questions

1)  x+y=25  <--- total questions
2)  2x+3y=66 <--- total points

Using substitution:
2x+3(25-x)=66
2x+75-3x=66
75-66=x
x=9 
y=25-9=16 
there are 9 - 2pt problems and 16 - 3pt problems

Tuesday, January 28, 2014

What are the rational routes of 8x^3+2x^2-5x+1=0 ?

By using synthetic division we can write:
8x^3+2x^2-5x+1=(x+1)(8x^2-6x+1)
then by the quadratic equation, factoring, or some other method we get
8x^3+2x^2-5x+1=(x+1)(2x-1)(4x-1)
The roots are: {-1, 1/2 1/4}