Q. Use Pascal's Triangle to expand (2−5y)4. Express your answer in simplest form.Answer:
Identify Row: Identify the row of Pascal's Triangle that corresponds to the exponent 4. The row for the exponent 4 is the fifth row (starting with row 0 for the exponent 0), which is 1,4,6,4,1.
Write Terms: Write out the terms using the binomial coefficients from Pascal's Triangle.The terms will be:1×(2)4×(−5y)0+4×(2)3×(−5y)1+6×(2)2×(−5y)2+4×(2)1×(−5y)3+1×(2)0×(−5y)4
Simplify Terms: Simplify each term. 1×(16)×1+4×(8)×(−5y)+6×(4)×(−5y)2+4×(2)×(−5y)3+1×1×(−5y)4=16−160y+6×4×25y2−8×125y3+625y4
Perform Multiplications: Continue simplifying by performing the multiplications.=16−160y+600y2−1000y3+625y4
Final Expression: Write the final expression in standard polynomial form, with the terms in descending order of the exponent.=625y4−1000y3+600y2−160y+16
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