Answer:
The answer to your question is:
Step-by-step explanation:
12.-
x² - 6x = 5
x² - 6x + (3)² = 5 + (3)²
x² - 6x + 9 = 5 + 9
(x - 3)² = 14
13.- x² - 6x = 12
x² - 6x + (3)² = 12 + (3)²
x² - 6x + 9 = 12 + 9
(x - 3)² = 21
x - 3 = ±√21
x1 = √21 + 3 x2 = -√21 + 3
x1 = 7.58 x2 = -1.58
14.- 2x² - 24x = - 20 Divide by 2
x² - 12 x = -10
x² - 12x + (6)² = - 10 + (6)²
x² - 12x + 36 = - 10 + 36
( x - 6) ² = 26
x - 6 = ±√26
x1 = √26 + 6 x2 = -√26 + 6
x1 = 11.1 x2 = 0.9
Answer:
x is 71
Step-by-step explanation:
X + 72 + 37 = 180 ( Sum of angles in a triangle)
X = 180 - 72 - 37
X = 71
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:
All real numbers less than or equal to
Step-by-step explanation: