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3 years ago

Solve using system by elimination: -3x + 4y = -18 x = -2y - 4

Mathematics

1 answer:

Jet001 [13]3 years ago

7 0

Step-by-step explanation:

equation 1 : -3x + 4y = -18

equation 2: x = -2y -4

transformed equation 2: x + 2y = -4

-3x + 4y = -18

x + 2y = -4

By elimination means we have to make one variable equal to zero or we have to take one variable out of the whole equation.

Let's eliminate the variable x. To do so, let's multiple the second equation to +3. Therefore,

-3x + 4y = -18

(3)x + (3)(2y) = (3)(-4)

-3x + 4y = -18

3x + 6y = -12

Now that both equations have the same value of x but different signs, we can now eliminate x by adding the two equations.

-3x + 4y = -18

3x + 6y = -12

0 + 10y = -30

Dividing both sides by 10, we have y = -3.

Now that we have the value of y, we can just substitute the value of y into either one of the equation OR we can do the process again but this time we need to eliminate y to find the value of x.

-3x + 4y = -18

x + 2y = -4

To eliminate y, we need to multiply the second equation by -2.

-3x + 4y = -18

(-2)x + (-2)2y = -4(-2)

-3x + 4y = -18

-2x - 4y = 8

Now that we have the same values but different signs of y, we can now add the two equations again.

-3x + 4y = -18

-2x - 4y = 8

-5x + 0 = -10

Dividing both sides by -5, we have x = 2.

CHECKING:

Let's take the second original equation,

x = -2y -4

Let's substitute the values we have found into the equation:

2 = -2(-3) - 4

2= 6 - 4

2 = 2

Both sides of the equation produced the same values. Therefore, the values are correct.

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Answer:

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275×2 would be how many miles she drove in 10 hours rght ? 275×2=550

550 miles in 10 hours

we know one hour is 55 miles & 5 hours is 275 & 10 hours is 550

10 hours plus 3 hours = 13 hours right ?

55 ×3 = 165

550 +165=715

715 miles in 13 hours

Step-by-step explanation:

715÷13 to get how many miles she drove in one hour .

=55 miles in 1 hour .

then multiply 55 ×5 to get how many miles she drove in 5 hours

55×5=275

275 miles in 5 hours

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3 years ago

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maria [59]

Answer:

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2 years ago

Solve the system of equations. \begin{aligned} & -5x+13y = -7 \\\\ & 5x+4y=24 \end{aligned} −5x+13y=−7 5x+4y=24 x= e

riadik2000 [5.3K]

Answer:

The solution of the given equations

x =4 , y = 1

Step-by-step explanation:

Explanation:-

Step(l):-

Given the system of equations -5x+13y = -7 ..(l)

5x+4y=24 ..(ll)

Step(ll)

Adding (l) and (ll) equations and cancelling '5x' terms we get

13y+4y = -7 +24

17y = 17

dividing '17' on both sides, we get

y=1

Step(lll):-

Substitute y=1 in equation (l) , we get

-5x+13y = -7

-5x + 13(1) = -7

subtracting '13' on both sides, we get

-5x +13 -13= -7 -13

-5x = -20

Dividing '-5' on both sides, we get

$x = \frac{-20}{-5}$

x = 4

Conclusion:-

The solution of the given equations

x =4 , y = 1

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4 years ago

-5+6 3/5=? I need a answer before tomorrow please help!

Svetach [21]

Answer:

-5+6 3/5= 1.6

Step-by-step explanation:

hope that helps!!!!

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3 years ago

Read 2 more answers

Help :D .......................

LUCKY_DIMON [66]

Answer:

The circunference is represented by the equation is $x^{2}+y^{2}-6\cdot x +4\cdot y +9=0$ .

The graph of this function is presented in the attachment.

Step-by-step explanation:

The general equation of the circunferece is defined by the following formula:

$x^{2}+y^{2}+A\cdot x + B\cdot y + C = 0$ (1)

We can determine the value of the coefficients by knowing three distinct points: $(x_{1}, y_{1}) = (3,0)$ , $(x_{2},y_{2}) = (5,-2)$ , $(x_{3},y_{3}) = (1, -2)$