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If a - b = 4 and a² - b² =12, what is the value of a + b?.

help.​

User Anatolii Stepaniuk
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2 Answers

13 votes
13 votes

Answer:

3

Explanation:

I have made it in above picture

hope it helps

If a - b = 4 and a² - b² =12, what is the value of a + b?. help.​-example-1
User Aleksander Pohl
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16 votes
16 votes

Answer:

a² - b² = ± 32

Explanation:

⇒ a + b = 4

⇒ a = 4 - b ... ( 1 )

Substituting this in another equation we get,

⇒ ab = -12

⇒ ( 4 - b ) ( b ) = -12

⇒ 4b - b² = -12

⇒ b² - 4b - 12 = 0

⇒ b² - 6b + 2b - 12 = 0

⇒ b ( b - 6 ) + 2 ( b - 6 ) = 0

⇒ ( b + 2 ) ( b - 6 ) = 0

⇒ b = -2, 6

Case 1: If b = -2

⇒ a = 4 - b

⇒ 4 - ( -2 ) = 4 + 2 = 6

Case 2: If b = 6

⇒ a = 4 - b = 4 - 6 = -2

Hence the numbers are 6 and -2.

⇒ a² - b² = ?

Case 1: a = 6 and b = -2

⇒ ( 6 )² - ( -2 )²

⇒ 36 - 4 = 32

Case 2: a = -2, b = 6

⇒ ( -2 )² - ( 6 )²

⇒ 4 - 36 = -32

Hence the answer for a² - b² can be ± 32 depending on the values of a and b.

hope it help a little bit.

User Quizzie
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