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26 votes
26 votes
If y²-x=7, find the positive value of when x=9.​

User Amina
by
3.2k points

2 Answers

22 votes
22 votes

Answer:

y = + 4

Explanation:

y² - x = 7 ← substitute x = 9 into the equation

y² - 9 = 7 ( add 9 to both sides )

y² = 16 ( take square root of both sides )

y = ±
√(16) = ± 4

the positive value of y when x = 9 is + 4

User Blerta
by
2.7k points
20 votes
20 votes

Answer:

4

Explanation:

when x = 9:

⇒ y² - 9 = 7

⇒ y² = 7 + 9

⇒ y² = 16

⇒ y = √16

⇒ y = ±4

Therefore, the positive value of y = 4

User Ashraf
by
2.3k points