Question

Explain, in complete sentences, how you would expand (7x + 4y)3 using Pascal's Triangle.

Answer 1

Pascal's triangle gives the coefficients of the terms of the expansion of (a + b)^n, where n is the n'th line of Pascal's triangle

so (7x + 4y)^3 corresponds to the third line of pascal's triangle, which will be 1 3 3 1

so when we expand, we get (1)*(7x)^3 + (3)*(7x)^2*(4y)^1 + (3)*(7x)^1*(4y)^2 + (1)*(4y)^3