Question

8)(3x + 5y = 212x - y = 1​

Answer 1

Ответ:

у=-1+2х

3х+5(-1+2х)=21

3х-5+10х=21

13х=26

х=2

у=-1+2*2

у=3

Answer 2

Ответ:

3x+5y=21. 3x+5y=21. 3x+5(2x-1)=21.

-y=1-2x y=2x-1. Y=2x-1

3x+10x-5=21. 13x=26 x=2

Y=2x-1. Y=2*2-1=4-1=3

X=2 y=3

Answer 3

You have provided a system of two linear equations with two variables, x and y. To solve this system of equations, you can use either the substitution method or the elimination method. I will use the elimination method to solve it.

Here are the equations:

1. 3x + 5y = 21
2. 2x - y = 1

To solve this system of equations, you can eliminate one of the variables by adding or subtracting the equations. In this case, we can eliminate the variable y by adding the two equations together. Here's how you can do it:

Multiply the second equation by 5 to make the coefficients of y in both equations equal:

1. 3x + 5y = 21
2. 10x - 5y = 5

Now, add the two equations together:

(3x + 5y) + (10x - 5y) = 21 + 5

This simplifies to:

13x = 26

Now, divide both sides by 13 to solve for x:

x = 26 / 13 x = 2

Now that we have found the value of x, we can substitute it back into one of the original equations to solve for y. Let's use the second equation:

2x - y = 1

Substitute x = 2:

2(2) - y = 1 4 - y = 1

Now, subtract 4 from both sides to solve for y:

-y = 1 - 4 -y = -3

Multiply both sides by -1 to solve for y:

y = 3

So, the solution to the system of equations is:

x = 2 y = 3