The teacher will be very surprised to see your correct solution 😉
4 = 7 - 6*(5*x - 1)
4 = 7-6*(5*x-1)
4 = 7-6*5*x+6*1
4 = 13 - 30*x
x = 9 / (30)
x1 = 3/10
sum
3/10
=
product
x1 = 0.3