Q. Use Pascal's Triangle to complete the expansion of (r+s)4. r4+4r3s+r2s2+4rs3+s4
Identify Pascal's Triangle: Pascal's Triangle for the 4th row is 1,4,6,4,1. These numbers are the coefficients for the expansion.
Determine Missing Term: The missing term is the coefficient for r2s2, which is the 3rd term in the expansion, so we use the 3rd number in the 4th row of Pascal's Triangle, which is 6.
Calculate Complete Expansion: The complete expansion is r4+4r3s+6r2s2+4rs3+s4.
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