Q. Use Pascal's Triangle to expand (3z−4)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 in Pascal's Triangle is the fifth row (starting with row 0 for the exponent 0), which is 1,4,6,4,1.
Write Expansion Terms: Write out the terms of the expansion using the coefficients from Pascal's Triangle.The expansion will have the form: (a+b)4=1⋅a4⋅b0+4⋅a3⋅b1+6⋅a2⋅b2+4⋅a1⋅b3+1⋅a0⋅b4.In our case, a=3z and b=−4.
Substitute and Simplify: Substitute a=3z and b=−4 into the expansion and simplify each term.The expansion becomes: 1⋅(3z)4⋅(−4)0+4⋅(3z)3⋅(−4)1+6⋅(3z)2⋅(−4)2+4⋅(3z)1⋅(−4)3+1⋅(3z)0⋅(−4)4.
Calculate Each Term: Calculate each term separately.1st term: 1∗(3z)4∗(−4)0=1∗81z4∗1=81z42nd term: 4∗(3z)3∗(−4)1=4∗27z3∗(−4)=−432z33rd term: 6∗(3z)2∗(−4)2=6∗9z2∗16=864z24th term: 4∗(3z)1∗(−4)3=4∗3z∗(−64)=−768z5th term: 1∗(3z)0∗(−4)4=1∗1∗256=256
Combine for Final Form: Combine all the terms to get the final expanded form.The expanded form is: 81z4−432z3+864z2−768z+256.
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