Q. Use Pascal's Triangle to expand (5y2+x2)3. Express your answer in simplest form.Answer:
Identify Row: Identify the row of Pascal's Triangle that corresponds to the exponent of the binomial expansion.Since we are expanding (5y2+x2)3, we need the 4th row of Pascal's Triangle, which corresponds to the coefficients for a cubic expansion.The 4th row of Pascal's Triangle is 1,3,3,1.
Write Terms: Write out each term of the expansion using the binomial theorem and the coefficients from Pascal's Triangle.The binomial theorem tells us that (a+b)n=Σ((kn))⋅a(n−k)⋅bk, where Σ denotes the sum over k from 0 to n.For (5y2+x2)3, we have:1⋅(5y2)3⋅(x2)0+3⋅(5y2)2⋅(x2)1+3⋅(5y2)1⋅(x2)2+1⋅(5y2)0⋅(x2)3
Calculate Terms: Calculate each term of the expansion.Now we will calculate each term:1×(5y2)3×(x2)0=1×(125y6)×(1)=125y63×(5y2)2×(x2)1=3×(25y4)×(x2)=75y4x23×(5y2)1×(x2)2=3×(5y2)×(x4)=15y2x41×(5y2)0×(x2)3=1×(1)×(x6)=x6
Combine for Final Form: Combine all the terms to write the final expanded form.The final expanded form of (5y2+x2)3 is:125y6+75y4x2+15y2x4+x6
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