Question

if one zero of polinomial 3x^2-8x-(2k-1) is seven times the other ,find both zeros and value of k

Answer 1

α=7β

α+β=  -b/a
 α+7α =  -(-8)/3
8α = 8/3
α=1/3

αβ=c/a
α*7α = -2k+1
7α²= -2k+1
7*(1/3)² = -2k +1

7/9 = -2k +1
-2k= 7/9 - 1
-2k = 7/9 - 9/9
-2k = (7-9)/9
-2k = -2/7
2k = 2/7
k= 1/7


And you can determine the value of β by substitution 

Answer 2

Hope it's the solution you are looking for..