SOLUTION: Can you please help me solve this equation? 25/2 x²+15x+9/2=0 it reads as: twenty-five halves x squared plus fifteen x plus nine halves equals zero i know you have to mult

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Can you please help me solve this equation? 25/2 x²+15x+9/2=0 it reads as: twenty-five halves x squared plus fifteen x plus nine halves equals zero i know you have to mult      Log On


   

Question 195350: Can you please help me solve this equation?
25/2 x²+15x+9/2=0
it reads as: twenty-five halves x squared plus fifteen x plus nine halves equals zero
i know you have to multiply everything by the LCD (at least, i think so), but i'm really lost and confused, do you think you could explain this to me??
thanks!
-Chelsea
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
%2825%2F2%29%2Ax%5E2+%2B+15x+%2B+9%2F2+=+0
Multiply both sides by 2
25x%5E2+%2B+30x+%2B+9+=+0
Use the quadratic equation
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
a+=+25
b+=+30
c+=+9
x+=+%28-30+%2B-+sqrt%28+30%5E2-4%2A25%2A9+%29%29%2F%282%2A25%29+
x+=+%28-30+%2B-+sqrt%28+900+-+900+%29%29+%2F+50+
x+=+-+30%2F50
x+=+-+3%2F5
check the answer:
25%2F2+x%B2+%2B+15x+%2B+9%2F2+=+0
%2825%2F2%29%2A+%28-3%2F5%29%B2+%2B+15%2A%28-3%2F5%29+%2B+9%2F2+=+0
9%2F2+-+9+%2B+9%2F2+=+0
9+-+18+%2B+9+=+0
0+=+0
OK
I'll draw the graph of this. It touches the x-axis in 1 place,
so there is only 1 root
+graph%28+400%2C+400%2C+-3%2C+1%2C+-2%2C+10%2C+%2825%2F2%29%2Ax%5E2+%2B+15x+%2B+9%2F2+%29+