Find the coefficient of the indicated term in the expansion of the binomial.

Question

y³

 term of (y + 3)⁴

Answer 1

12

12y^3

4y^3(3) = 12y^3

1

11

121

1331

14641

5th line on Pascal's triangle gives the coefficients 4C1 = 4!/1!3! = 4

y^4 + 4y^3(3) + 6y^2(3)^2 + 4y(3)^3 + (3)^4

y^4 + 12y^3 + 54y^2 + 108y + 81 = (y+3)^4 = (y^2 + 6y + 9)^2 the y^3 term is y^2(6y) + 6y(y^2) = 12y^2