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3 years ago

Solve the system of equations by elimination 3x+4y=31 2x-4y=-6

2 answers:

5 0

3x + 4y = 31
2x - 4y = -6

*The +4 and -4 in the center of the equation cancel out because 4-4 = 0*

3x = 31
2x = -6
------------

*add like terms*

3x + 2x = 5x

31 - 6 = 25

So now you should have this written on your paper ... > 5x = 25

*Divide by 5 on each side*

5x = 25
_ _
5 5

x = 5

Kobotan [32]3 years ago

5 0

Answer:

x = 5 and y = 4

Step-by-step explanation:

In elimination method we solve a system of two variable equations by eliminating one variable by operating the equations.

Given system of equations,

3x + 4y = 31 ------(1)

2x - 4y = -6 --------(2),

Equation (1) + equation (2),

3x + 2x = 31 - 6

5x = 25

x = 5

From equation (1),

3(5) + 4y = 31

15 + 4y = 31

4y = 16

y = 4

Hence, the solution of the given equations is, x = 5, y = 4

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Answer:

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2 years ago

Shannon saves 1235 in november. In november, she saved $250 less than she did in december. How much money did she save in the tw

madam [21]

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4 years ago

three times a number is subtracted from another number and the difference is 3. The sum of the two numbers is 31. What is the sm

Aleksandr-060686 [28]

ANSWER

The smaller number is 7.

EXPLANATION

Let the numbers be x and y.

Then we have;

y-3x=3... eqn (1)

If the sum of the numbers is 3 then,

y+x=31... eqn (2)

Eqn(2) - Eqn (1)

x--3x=31-3

$4x = 28$

Divide both sides by 4,

$x = 7$

We put x=7 into the second equation,

y+7=31

y=31-7

y=24

The smaller of the two numbers is 7.

6 0

3 years ago

Read 2 more answers

HELP PLEASE ASAP 30 PTS I’ll MARK YOU BRAINLIEST

tester [92]

Answer:

x=50 ∠BCX=65

Step-by-step explanation:

The angles is a triangle add up to 180 so

70+45+∠BCX=180 so

115+∠BCX=180 (subtract 115 from both sides)

∠BCX=65

A line adds up to 180

so 2x+15+65=180

so 2x+80=180 (subtract 80 from both sides)

2x=100 (divide by 2)

x=50

8 0

4 years ago

This is solving differential equations by sepeartion of variables

Brums [2.3K]

$\mathrm dy+k(y-70)\,\mathrm dx=0$

Separating variables gives

$\dfrac{\mathrm dy}{y-70}=-k\,\mathrm dx$

Integrating both sides gives

$\displaystyle\int\frac{\mathrm dy}{y-70}=-k\int\mathrm dx$
$\ln|y-70|+C_1=-kx+C_2$
$\ln|y-70|=-kx+C$

Solving for $y$ gives

$e^{\ln|y-70|}=e^{-kx+C}$
$y-70=e^{-kx}e^C$
$y=Ce^{-kx}+70$

As $y(1)=140$ , you get

$140=Ce^{-k}+70$
$70=Ce^{-k}$
$C=70e^k$

so the particular solution to this ODE is

$y=70e^ke^{-kx}+70$
$y=70e^{k(1-x)}+70$

Unless you have any more information, you're done.

5 0

3 years ago