Kelly multiplied (4x + 11) (4x – 11) and got an answer of 4x2 – 88x – 121. Is she correct? Explain by showing your solution.
Answers
Answer:
→(4x++11)(4x-11) [(a²-b²)=(a+b)(a-b)]
=8x²-121
hence kelly is wrong
Given :- Kelly multiplied (4x + 11) (4x – 11) and got an answer of 4x² – 88x – 121.
To Find :- Is she correct ? Explain by showing your solution.
Solution :-
→ (4x + 11)(4x - 11)
→ 4x(4x - 11) + 11(4x - 11)
→ 4x * 4x - 4x * 11 + 11 * 4x - 11 * 11
→ 16x² - 44x + 44x - 121
→ (16x² - 121) = Correct Solution.
Kelly's Solution = (4x² - 88x - 121)
therefore, Kelly's solution is incorrect .
Another way :-
→ (4x + 11)(4x - 11)
using (a + b)(a - b) = a² - b² . Taking a = 4x and b = 11
→ a² - b²
→ (4x)² - (11)²
→ (16x² - 121)
therefore, Kelly's solution is incorrect .
Learn more :-
solution of x minus Y is equal to 1 and 2 X + Y is equal to 8 by cross multiplication method
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