A) find, in ascending powers of X, the first 4 terms of the expansion (1+X)^7. B) Hence, find the coefficient of y^3 in the expansion of (1+y-y^2)^7.

Please help, this is mindbending. I understand (A) but not (B)​

10x

step-by-step explanation:

the greatest common factor 30 and 20 is 10

5 is a common factor of 30 and 20 but 10 is also a factor and 10 is greater than 5 so 5 will definitely not be apart of our answer

now the most amount of x's you factor our is just 1 factor of 1

so 10x the gcf of the terms in the polynomial

step-by-step explanation:

the true ones are a b and d