Combine like terms: 12b+15+7b-8+7x=

Step-by-step explanation:

Like terms have same variables and exponents

12b and 7b are like terms

15 & -8  are like terms

12b + 15 + 7b - 8 + 7x = 12b + 7b + 15 - 8 + 7x

                                   = 19b + 7 + 7x

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18