Question

Find the coefficient of x in the expansion of (x + 2/x^2)^7

Answer 1

The coefficient of x has a power of 1.
If you know the binomial expansion, (or pascal's triangle), you'll know that in that the power of the first term in the binomial, has to add up to the exponent along with the power in the second term.

Basically:
\[(a + b)^n\]
For any expanded term:
\[a^{c}b^{d} where c+d = n\]

Answer 2

Now according to the binomial, there's a 1/x^2 in the 2nd term,
So basically, you'll have to find a way to make the first term (a^c)(b^d) somehow a*b will leave an x, and c + d = n