Help asap-3(1+6j)=14-j

Insert 2 sets of parentheses to make each sentence true: 2 x 14 - 9 - 17 - 14 = 7

Mandarinka [93]

It’s most definitely C

6 0

3 years ago

Solve the equation of exponential decay. The population of a city is expected to be 440,000 in 2020. This is a decline of 12% fr

DIA [1.3K]

Answer:

about 340,000

Step-by-step explanation:

In 10 years, the population dropped to 0.88 of what it was in 2010. At the same rate, in 20 more years, it will drop to 0.88² of what it was in 2020:

2040 population = 440,000·0.88² ≈ 340,000

5 0

3 years ago

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I need help 6x-2y=10 x-2y=-5 solve by elimination

dem82 [27]

<h3>Explanation</h3>

Given the system of equations.

$\begin{cases} 6x - 2y = 10 \\ x - 2y = - 5 \end{cases}$

Solve the system of equations by eliminating either x-term or y-term. We will eliminate the y-term as it is faster to solve the equation.

To eliminate the y-term, we have to multiply the negative in either the first or second equation so we can get rid of the y-term. I will multiply negative in the second equation.

$\begin{cases} 6x - 2y = 10 \\ - x + 2y = 5 \end{cases}$

There as we can get rid of the y-term by adding both equations.

$(6x - x) + ( - 2y + 2y) = 10 + 5 \\ 5x + 0 = 15 \\ 5x = 15 \\ x = \frac{15}{5} \longrightarrow \frac{ \cancel{15}}{ \cancel{5}} = \frac{3}{1} \\ x = 3$

Hence, the value of x is 3. But we are not finished yet because we need to find the value of y as well. Therefore, we substitute the value of x in any given equations. I will substitute the value of x in the second equation.

$x - 2y = - 5 \\ 3 - 2y = - 5 \\ 3 + 5 = 2y \\ 8 = 2y \\ \frac{8}{2} = y \\ y = \frac{8}{2} \longrightarrow \frac{ \cancel{8}}{ \cancel{2}} = \frac{4}{1} \\ y = 4$

Hence, the value of y is 4. Therefore, we can say that when x = 3, y = 4.

Answer Check by substituting both x and y values in both equations.

First Equation

$6x - 2y = 10 \\ 6(3) - 2(4) = 10 \\ 18 - 8 = 10 \\ 10 = 10 \longrightarrow \sf{true} \: \green{ \checkmark}$

Second Equation

$x - 2y = - 5 \\ 3 - 2(4) = - 5 \\ 3 - 8 = - 5 \\ - 5 = - 5 \longrightarrow \sf{true} \: \green{ \checkmark}$

Hence, both equations are true for x = 3 and y = 4. Therefore, the solution is (3,4)

<h3>Answer</h3>

$\begin{cases} x = 3 \\ y = 4 \end{cases} \\ \sf \underline{Coordinate \: \: Form} \\ (3,4)$

8 0

3 years ago

I need help with a MathsWatch question!

KIM [24]

To find the area of a circle, you do π × diameter (in this case 10). They have told you to use 3.142 as π, so you do 3.142 × 10 = 31.42. Because it's a semi-circle, you need to halve 31.42 to get 16.21, which is the answer

6 0

3 years ago

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The resquest of the y'+6y=e^4t, y(0)=2

kotegsom [21]

This is a linear differential equation of first order. Solve this by integrating the coefficient of the y term and then raising e to the integrated coefficient to find the integrating factor, i.e. the integrating factor for this problem is e^(6x).
Multiplying both sides of the equation by the integrating factor: 

(y')e^(6x) + 6ye^(6x) = e^(12x) 

The left side is the derivative of ye^(6x), hence 

d/dx[ye^(6x)] = e^(12x) 

Integrating 

ye^(6x) = (1/12)e^(12x) + c where c is a constant 

y = (1/12)e^(6x) + ce^(-6x) 

Use the initial condition y(0)=-8 to find c: 

-8 = (1/12) + c 
c=-97/12 

Hence 

y = (1/12)e^(6x) - (97/12)e^(-6x)

7 0

3 years ago