Expert: Richard J. Raridon - 9/18/2005

Question
1) 3(x squared-4)-5x=o

2) x squared /2= 11- 3x/4

3) x squared-2x=3


4) If the square of a possitive number is increased by 4 times the number, the sum is 17. What is the number?

5) The length of a rectangle is 2and1/2 times its width. Its area is 90 square units. What are its dimensions.

6) The difference of two possitive numbers is 6. Their product is 223 less than the sum of their squares. What is the two numbers?

Answer
1) 3(x^2 -4) -5x = 3x^2 -5x -12 = 0 = (3x+4)(x-3)
so x = 3, -4/3
2) x^2/2 = 11 -3x/4 so 2x^2 +3x-44 = 0 = (2x+11)(x-4)
and x = 4,-11/2
3) x^2 -2x -3 = (x-3)(x+1) so x = 3,-1
4) Do you mean x^2 +4x = 17?   that won't factor
5) L = 2.5W
LW = 90 = (2.5W)W = 90 so W = 6 and L = 15
6) x-y = 6
xy = x^2+y^2-223
substitute y=x-6
x(x-6) = x^2 +(x-6)^2 -223
x^2 -6x -187 = (x-17)(x+11) so the numbers are 17 and 11