Question

{ x - 2y = - 11 ; 7x - 4y = 7}​

Answer 1

Ответ:

x=5.8 y=8.4

Пошаговое объяснение:

x-2y=-11

7x-4y=7

x=2y-11

7(2y-11)-4y=7

14y-77-4y=7

10y=7+77

10y=84

y=84÷10=8,4

x=2×8,4-11=16,8-11=5,8

Answer 2

Ответ: x=5.8; y=8.4

Пошаговое объяснение:

Answer 3

To solve the system of equations:

1. $x - 2y = -11$
2. $7x - 4y = 7$

We can use the method of substitution or elimination. Let's use the elimination method:

First, let's manipulate the first equation so that the coefficients of $y$ in both equations match. Multiply the first equation by 2:

$2(x - 2y) = 2(-11)$ $2x - 4y = -22$

Now we have two equations:

1. $2x - 4y = -22$
2. $7x - 4y = 7$

Now, subtract the second equation from the first equation to eliminate $y$:

$(2x - 4y) - (7x - 4y) = (-22) - 7$ $-5x = -29$

Divide both sides by -5:

$x = \frac{-29}{-5}$ $x = \frac{29}{5}$

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

$x - 2y = -11$ $\frac{29}{5} - 2y = -11$

Subtract $\frac{29}{5}$ from both sides:

$-2y = -\frac{60}{5}$

Simplify:

$y = \frac{30}{5}$ $y = 6$

So, the solution to the system of equations is $x = \frac{29}{5}$ and $y = 6$.