Question

Which of the following is the difference between the squares of 21 and 22 ? *

2 points

21

22

42

43

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Answer 1

Explanation:

please follow me

a^2 - b^2 = 21 Equation 1

3a^2 + b^2 = 79 Equation 2

Equation 1 + Equation 2

a^2 + 3 a^2 - b^2 + b^2 = 21 + 79

4 a^2 = 100

a^2 = 25

a = 5

b^2 = 25 -21 = 4

b = 2

Answer 2

Answer:

21

Explanation:

'i want to see the answer which of the following is the difference between the square of 21 and 22