The area of a square is 81 square centimeters. What is the perimeter of the square?
1 answer:
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Answer:
second option
Step-by-step explanation:
Given
+ 6x² + 5 = 0
let u = x², then
u² + 6u + 5 = 0 ← in standard form
(u + 1)(u + 5) = 0 ← in factored form
Equate each factor to zero and solve for u
u + 1 = 0 ⇒ u = - 1
u + 5 = 0 ⇒ u = - 5
Change u back into terms of x, that is
x² = - 1 ( take the square root of both sides )
x = ± = ± i ( noting that
= i ), and
x² = - 5 ( take the square root of both sides )
x = ± = ±
= ±
×
= ± i
Solutions are x = ± i and x = ± i
Answer:
b = -3
Step-by-step explanation:
Step 1: Simplify both sides of the equation.
6b+14=−7−b
6b+14=−7+−b
6b+14=−b−7
Step 2: Add b to both sides.
6b+14+b=−b−7+b
7b+14=−7
Step 3: Subtract 14 from both sides.
7b+14−14=−7−14
7b=−21
Step 4: Divide both sides by 7.
b= -3