no calculator

    \begin{align*}f(x)&=\dfrac{3x^2-5x+11}{7x^2-2x-5}\end{align*}

The values a and b are not included in the domain of the rational function above. What is the value of a+b ?

A)
B)
C)
D)

 


 

Comments (4)

I got the one but not the -5/7. You have 1 and half minutes average time do these problems do you really think you can use the quadractic equation in that little time? I think Jeff b is a little more on target.

The only way I could figure it out was to realize 1 for x in denominator provided zero( I was lucky to see it) then I knew that 1 less than any of the answers would provide the correct solution when f(x) also equaled zero

since d was less than one, we got a negative value 2/7-1 =-5/7 when that was plugged into the denominator.
(5^2/7^2)*7 = 25/7, -5/7* -2 =+10/7 , -5
it provided ( 25/7 + 10/7) -5 = 0
35/7 = 5, 5 – 5 = 0

I had also factored out the denominator and got the sames as jeff b ( -7x-5) (-x+1) but could not put it together. that was the most efficient way.

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