Question

factorise 5x²-7x+1 and find 1/a + 1/b, where a and b are its factors​

Answer 1

Answer:

7

Step-by-step explanation:

by factor theorem,

5x^2-7x+1=0

use completing squre method

x^2-7/5x+1/5=0

x^2-2(7/10) = -1/5

x^2-2(7/10)x+(7/10)^2-(7/10)^2=-1/5

(x-7/10)^2 -(7/10)^2= -1/5

(x-7/10)^2 = 49/100 - 1/5

so a=x=7+squre root29/10

b=x=7-squre root 29/10

1/a +1/b = 7