Question

Which set of coefficients of the terms in the expansion of the binomial (x + y)3 is correct?
1, 3, 3, 1
1, 4, 4, 1
1, 2, 2, 1
1, 5, 5, 1

Answer 1

well if you split it out a bit its

\[(x+ y)^3 = (x + y)^2 \times (x + y) =(x^2 + 2xy + y^2)(x + y)\]

distribute that and't you'll find the answer..

Answer 2

another way is the 1st and last terms have a coefficient of 1

the 2nd and 2nd last terms have a coefficient that is the same as the power

Answer 3

I see, so it would be 1,3,3,1

Answer 4

correct