Let a and b be the solutions to 5x2−11x+4=0. Find 1/a+1/b .
According to Vieta's Formula, the sum of the two roots are −b/a and the product of the roots is c/a for an equation in the form ofax2+bx+c=0 .
In this case, a=5,b=−11, and c=4 .
We can factor 1/a+1/b to become (a+b)/ab. We can plug our values for a, b, and c in for the sum and product of the roots, giving us the answer of 11/4 . We don't need to solve for the roots.
Therefore our answer is 11/4.
I hope this helped.
Use Vieta's formulas.
sum of roots = -b/a
product of roots = c/a
then do some manipulation, don't be lazy