Question

13x-8y=31,3x-0,2y=-16​

Answer 1

ответ на фото, делала сама

Answer 2

To solve this system of linear equations:

1. 13x - 8y = 31
2. 3x - 0.2y = -16

You can use either the substitution method or the elimination method. I'll use the elimination method here.

First, multiply both sides of the second equation by 10 to get rid of the decimal:

2 * (3x - 0.2y) = 2 * (-16) 6x - 2y = -32

Now, your system of equations is:

1. 13x - 8y = 31
2. 6x - 2y = -32

Now, we can eliminate one of the variables (y) by adding the two equations:

(13x - 8y) + (6x - 2y) = 31 - 32

Combine like terms:

19x - 10y = -1

Now, we have a new equation:

3. 19x - 10y = -1

You can solve this equation for either x or y. Let's solve it for x:

19x - 10y = -1

19x = 10y - 1

x = (10y - 1) / 19

Now, we can substitute this expression for x back into either of the original equations to find the value of y. I'll use the first equation:

13x - 8y = 31

13((10y - 1) / 19) - 8y = 31

Now, you can solve for y:

13(10y - 1) / 19 - 8y = 31

Multiply both sides by 19 to get rid of the fraction:

13(10y - 1) - 8y * 19 = 31 * 19

130y - 13 - 152y = 589

Combine like terms:

-22y - 13 = 589

Add 13 to both sides:

-22y = 589 + 13

-22y = 602

Now, divide by -22 to solve for y:

y = -602 / 22

y = -301 / 11

Now that you have found the value of y, you can substitute it back into the expression for x:

x = (10y - 1) / 19

x = (10 * (-301/11) - 1) / 19

x = (-3010/11 - 1) / 19

x = (-3010 - 11) / (11 * 19)

x = -3021 / 209

So, the solution to the system of equations is:

x = -3021/209 y = -301/11