Answer :

All you need to do is distribute the 8 into each of the terms in the parenthesis.

Your equation will then become

32x + 48y - 24z
When there is a number outside the parenthesis, you multiply. So we have multiply everything in the parenthesis with 8. Which is equal to 8 (4x) 8 (6y) 8(-3z) = 32x + 48y - 24z.