What is the ratio of the sector area to the area of the

Solve the simultaneous equations 3 2x - y = 7 xy = 15

ehidna [41]

Answer:

(5, 3 ) and (- $\frac{3}{2}$ , - 10 )

Step-by-step explanation:

Given the 2 equations

2x - y = 7 → (1)

xy = 15 → (2)

Rearrange (1) expressing y in terms of x , that is

y = 2x - 7 → (3)

Substitute y = 2x - 7 into (2)

x(2x - 7) = 15

2x² - 7x = 15 ( subtract 15 from both sides )

2x² - 7x - 15 = 0 ← in standard form

(x - 5)(2x + 3) = 0 ← in factored form

Equate each factor to zero and solve for x

x - 5 = 0 ⇒ x = 5

2x + 3 = 0 ⇒ 2x = - 3 ⇒ x = - $\frac{3}{2}$

Substitute these values into (3) for corresponding values of y

x = 5 : y = 2(5) - 7 = 10 - 7 = 3 ⇒ (5, 3 )

x = - $\frac{3}{2}$ : y = 2(- $\frac{3}{2}$ ) - 7 = - 3 - 7 = - 10 ⇒ (- $\frac{3}{2}$ , - 10 )

8 0

2 years ago

1. David trabajó hoy 7 1/3 horas y plantó 11 árboles. Le toma aproximadamente la misma cantidad de tiempo plantar cada árbol. ¿C

eimsori [14]

Sjsjsjsjsjdjdjsjs also Ian’s lol banksia

7 0

3 years ago

Besides 12 and 1, what is one factor of 12

BabaBlast [244]

One factor of 12 is 2. The other factors of 12 are 3, 4, and 6.

8 0

3 years ago

Read 2 more answers

Curtis plays a trivia game he earns 2 points for each correct answer and loses 0.25 points for each incorrect answer he get 21 c

Maslowich

Answer:

41

Step-by-step explanation:

Curtis is playing a trivia game.

Number of points earned for each correct answer = 2

Number of points lost for each correct answer = 0.25

Given that:

Number of correct answers given by Curtis = 21

Number of wrong answers given by Curtis = 4

To find:

Total score of the game by Curtis?

Solution:

First of all, let us find the points earned by correct answers.

Points earned by correct answers = Number of correct answers multiplied by Points earned on one correct answer.

Points earned by correct answers = 21 $\times$ 2 = 42

Now, let us find the points to be lost by wrong answers.

Points lost by wrong answers = Number of wrong answers multiplied by Points lost on one correct answer.

Points lost by wrong answers = 4 $\times$ 0.25 = 1

The score of the game can be calculated by subtracting the points lost from the points earned.

Score = 42 - 1 = 41

3 0

2 years ago

Solve (x + 4)2 – 3(x + 4) – 3 = 0 using substitution. u = Select the solution(s) of the original equation.

bezimeni [28]

Answer:

$\dfrac{-5-\sqrt{21}}{2},\ \dfrac{-5+\sqrt{21}}{2}$

Step-by-step explanation:

For the equation $(x+4)^2-3(x+4)-3=0$ use the substitution $u=x+4.$ Then the equation will take look

$u^2-3u-3=0.$

Solve this quadratic equation:

$D=(-3)^2-4\cdot 1\cdot (-3)=9+12=21,\\ \\u_{1,2}=\dfrac{-(-3)\pm \sqrt{21}}{2}=\dfrac{3\pm\sqrt{21}}{2}.$

Thus,

$x+4=\dfrac{3-\sqrt{21}}{2}\text{ or }x+4=\dfrac{3+\sqrt{21}}{2},\\ \\x_1=\dfrac{3-\sqrt{21}}{2}-4=\dfrac{-5-\sqrt{21}}{2}\text{ or }x_2=\dfrac{3+\sqrt{21}}{2}-4=\dfrac{-5+\sqrt{21}}{2}.$

8 0

3 years ago

Read 2 more answers