1. (5 + 4) x 2 + 6 - (2 x 2) - 1
2. 9 x 2 + 6 - 4 - 1
3. 18 + 6 - 4 - 1
4. 24 - 4 - 1
5. 20 - 1
6. 19
Answer:
Step-by-step explanation:
13.
<h3>Given</h3>
<u>Quadratic equation</u>
- 4x² - 3x - 4 = 0
- With the roots of α and β
<h3>To Find </h3>
- The quadratic equation with roots of 1/(3α) and 1/(3β)
<h3>Solution</h3>
<u>The sum and the product of the roots of the given equation:</u>
- α + β = -b/a ⇒ α + β = -(-3)/4 = 3/4
- αβ = c/a ⇒ αβ = -4/4 = - 1
<u>New equation is:</u>
- (x - 1/(3α))(x - 1/(3β)) = 0
- x² - (1/(3α) + 1/(3αβ))x + 1/(3α3β) = 0
- x² - ((3α + 3 β)/(3α3β))x + 1/(3α3β) = 0
- x² - ((α + β)/(3αβ))x + 1/(9αβ) = 0
- x² - (3/4)/(3(-1))x + 1/(9(-1)) = 0
- x² + 1/4x - 1/9 = 0
- 36x² + 9x - 4 = 0
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14.
<h3>Given</h3>
<u>Quadratic equation</u>
- 3x² +2x + 7 = 0
- With the roots of α and β
<h3>To Find </h3>
- The quadratic equation with roots of α + 1/β and β + 1/α
<h3>Solution</h3>
<u>The sum and the product of the roots of the given equation:</u>
- α + β = -b/a ⇒ α + β = -2/3
- αβ = c/a ⇒ αβ = 7/3
<u>New equation is:</u>
- (x - (α + 1/β))(x - (β + 1/α)) = 0
- x² - (α + 1/β + β + 1/α)x + (α + 1/β) (β + 1/α) = 0
- x² - (α + β + (α + β)/αβ )x + αβ + 1/αβ + 2 = 0
- x² - (-2/3 - (2/3)/(7/3))x + 7/3 + 1/(7/3) + 2 = 0
- x² - (-2/3 - 2/7)x + 7/3 + 3/7 + 2 = 0
- x² + (14 + 6)/21x + (49 + 9 + 42/21) = 0
- x² + 20/21x + 100/21 = 0
- 21x² + 20x + 100 = 0
Answer:
B and D
Step-by-step explanation:
Answer:
It's false, this number is a rational number.
Step-by-step explanation:
It's false, the kind of decimal where the same digits repeats forever are known as periodic decimals and they can be represented with fractions therefore they are a part of the rational numbers. To represent this number in a fraction form we need to first identify the part that repeats, in this case it's 7, since it's only one number we can insert it in the numerator and the denominator will have a 9, if it were two numbers the denominator would have a 99 and so on. So in this case:
7/9 = 0.7777...
