Plug in -7 for x in the equation...
f(x) = 3 - 2( - 7 )
f(x) = 3 + 14
f(x) = 17
We have
(a + b)² = a² + 2ab + b²
so that with a = x² and b = 5, we have
x⁴ + 10x² + 25 = (x² + 5)²
Next, we have
a² - b² = (a - b) (a + b)
so that with a = x and b = √5 i,
x² + 5 = x² - (-5) = (x - √5 i) (x + √5 i)
So, the complete factorization over the complexes is
(x - √5 i)² (x + √5 i)²
Answer:
Options (2) and (3)
Step-by-step explanation:
Let, 

-8 + 8i√3 = a² + b²i² + 2abi
-8 + 8i√3 = a² - b² + 2abi
By comparing both the sides of the equation,
a² - b² = -8 -------(1)
2ab = 8√3
ab = 4√3 ----------(2)
a = 
By substituting the value of a in equation (1),


48 - b⁴ = -8b²
b⁴ - 8b² - 48 = 0
b⁴ - 12b² + 4b² - 48 = 0
b²(b² - 12) + 4(b² - 12) = 0
(b² + 4)(b² - 12) = 0
b² + 4 = 0 ⇒ b = ±√-4
b = ± 2i
b² - 12 = 0 ⇒ b = ±2√3
Since, a = 
For b = ±2i,
a =
= 
= 
But a is real therefore, a ≠ ±2i√3.
For b = ±2√3
a = 
a = ±2
Therefore, (a + bi) = (2 + 2i√3) and (-2 - 2i√3)
Options (2) and (3) are the correct options.
Answer:
B) Going to the close store is cheaper.
Step-by-step explanation:
Cost of going to the next town:
(8.3mi/22mi) × $3.79 = $1.43
Cost of going to the close store:
(2.3mi/22mi) × $3.79 = $0.40