Question

3x + 4y = - 20 5x + 2y = - 10

Answer 1

Ответ:

(0; -5)

Объяснение:

$\left \{ {{3x + 4y = -20} \atop {5x + 2y = -10 | \cdot -2}} \right.\\\\\left \{ {{3x + 4y = -20} \atop {-10x - 4y = 20}} \right.\\\\\left \{ {{3x + 4y = -20} \atop {-7x = 0}} \right.\\\\\left \{ {{3x + 4y = -20} \atop {x = 0}} \right.\\\\\left \{ {{y = -5} \atop {x = 0}} \right.$

Answer 2

Ответ:

х = 0, у = –5

Подробнее на фото.

Answer 3

To solve this system of linear equations:

1. 3x + 4y = -20
2. 5x + 2y = -10

You can use the method of your choice, such as substitution or elimination. In this case, I'll use the elimination method. Let's multiply both sides of the second equation by 2 and the first equation by -2, so that when we add the equations, the y terms will cancel out:

Multiply the second equation by 2: 2(5x + 2y) = 2(-10) 10x + 4y = -20

Multiply the first equation by -2: -2(3x + 4y) = -2(-20) -6x - 8y = 40

Now, we have the following two equations:

1. 10x + 4y = -20
2. -6x - 8y = 40

Now, add these two equations to eliminate the y terms:

(10x + 4y) + (-6x - 8y) = (-20 + 40)

Simplify:

10x - 6x + 4y - 8y = 20

4x - 4y = 20

Now, divide both sides of this equation by 4 to solve for x:

(4x - 4y) / 4 = 20 / 4

x - y = 5

Now, you have the value of x: x = 5.

You can substitute this value back into either of the original equations to solve for y. Let's use the first equation:

3x + 4y = -20 3(5) + 4y = -20 15 + 4y = -20

Subtract 15 from both sides:

4y = -20 - 15 4y = -35

Now, divide by 4 to find the value of y:

4y / 4 = -35 / 4 y = -35 / 4

So, the solution to the system of equations is:

x = 5 y = -35/4