The teacher will be very surprised to see your correct solution 😉
6 = 8 - 5*(7*x - 1)
6 = 8-5*(7*x-1)
6 = 8-5*7*x+5*1
6 = 13 - 35*x
x = 7 / (35)
sum
1/5
=
product
x1 = 1/5
x1 = 0.2