How can i make 8 and 62/40 a proper mixed number

You can't make it proper.You can only simplify.
Step 1: Factor both the numerator and denominator down to prime factors:62 = 2 * 31 
40 = 23 * 5Step 2: Calculate the greatest common factor, GCF (also called greatest common divisor, GCD), by taking all the common prime factors of the numerator and denominator, by the lowest powers:gcd(2 * 31; 23 * 5) = 2 
Step 3: Divide both the numerator and denominator by their greatest common factor, GCF (also called the greatest common divisor, GCD):62/40 =
(2 * 31)/(23 * 5) = 
((2 * 31) : 2) / ((23 * 5) : 2) =
31/(22 * 5) =
31/20Step 4: Improper fraction, rewrite:31 : 20 = 1 and remainder = 11 => 
31/20 = (1 * 20 + 11) / 20 = 1 + 11/20 = 1 11/20 as a mixed number (also called mixed fraction).1 + 11 : 20 = 1.55 as a decimal number.

First you change 62/40 to a proper mixed number: 1 11/20

then you add 8 to 1 11/20 :

your final answer is 9 11/20

hope this helps :)