Question

3x + 5y = 21 8x - 3y = 7​

Answer 1

Пошаговое объяснение:

цифры к цифрам буквы к буквам

Answer 2

Ответ:

х=2, у=3

Пошаговое объяснение:

3x + 5y = 21|*3  

8x - 3y = 7​|*5  

9х+15у=63              х=2                                 Проверка:

40х-15у=35            8*2-3у=7                     3*2+5*3=21

-------------------         16-3у=7

49х=98                    -3у= -9

х=2                           у=3

Answer 3

You have a system of two linear equations with two variables:

1. 3x + 5y = 21
2. 8x - 3y = 7

To solve this system of equations, you can use the method of either substitution or elimination. Let's use the elimination method in this case:

First, you can multiply both sides of the first equation by 3 and the second equation by 5 to make the coefficients of y in both equations equal:

1. (3)(3x + 5y) = (3)(21) => 9x + 15y = 63
2. (5)(8x - 3y) = (5)(7) => 40x - 15y = 35

Now, you have the following two equations:

3. 9x + 15y = 63
4. 40x - 15y = 35

You can add equation 3 and equation 4 to eliminate the y variable:

(9x + 15y) + (40x - 15y) = 63 + 35

Combine like terms:

49x = 98

Now, divide both sides by 49 to solve for x:

x = 98 / 49 x = 2

Now that you have found the value of x, you can substitute it back into one of the original equations to find the value of y. Let's use the first equation:

3x + 5y = 21 3(2) + 5y = 21 6 + 5y = 21

Subtract 6 from both sides:

5y = 21 - 6 5y = 15

Now, divide both sides by 5 to solve for y:

y = 15 / 5 y = 3

So, the solution to the system of equations is:

x = 2 y = 3