How is solving 2x+c=d similar to solving 2x+1=9 for x? How are they different? How can you use x+c=d to solve 2x+1=9?

No

Step-by-step explanation:

We can't use 2x + c = d for solving 2x + 1 = 9 . Here we can find the value of x from 2x + 1 = 9.

Putting the value of x in 2x + c = d :-

But still we don't know the exact value of c & d . If in the question at least we could have got one exact value of either c or d , then we could find out the value of other variable.

(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

2nd one in the first row is correct