Question 64227: Please help
1.) The graph of -4x+2y=6 crosses the x-axis when x = ?
2.) Find the center and the radius from the equation of the circle in standard form (x-5)^2+(y+3)^2
3.) The formula for the area of a triangle is A=1/2bh. If a=20 and h=b-6, then what does b= ?
4. The solution set of the equation 4/x+2-2/x-4=-6/x^2-2x-8 is ?
Thank you!!
Answer by funmath(2933)   (Show Source):
You can put this solution on YOUR website! 1.) The graph of -4x+2y=6 crosses the x-axis when x = ?
Let y=0 and solve for x to find this:
-4x+2(0)=6
-4x+0=6
-4x/-4=6/-4
2.) Find the center and the radius from the equation of the circle in standard form (x-5)^2+(y+3)^2
Standard form of a circle is: , where (h,k)=center, and  =radius.
You forgot to include the =r^2 part so I can't tell you what the radius is, but the center (h,k)=(5,-3)
:
3.) The formula for the area of a triangle is A=1/2bh. If A=20 and h=b-6, then what does b= ?
20=(1/2)b(b-6)
2(20)=2(1/2)b(b-6)
40=b(b-6)
40=b^2-6b
40-40=b^2-6b-40
0=b^2-6b-40
0=(b-10)(b+4)
b-10=0 or b+4=0
b-10+10=0+10 or b+4-4=0-4
b=10 or b=-4
Since you can't have a negative dimension, we ignore -4 and say that  .
:
4. The solution set of the equation  is ?
 The LCD is (x+2)(x-4), multiply evertyhing by the LCD to clear your fractions.
Double check to make sure that the equation is defined at x=7 (it is), because you can get extraneous solutions with rational equations. If the solution had of been x=-2 or x=4, we would have had to reject it because it would have made one of the fractions undefined.
Happy Calculating!!!!
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