Question

21(x - y) = 48 + 20 x,19(y + x) = 100 + 12 y.​

Answer 1

Ответ:

21(x - y) = 48 + 20 x,           21x - 21y = 48 + 20x           x - 21y - 48 = 0

19(y + x) = 100 + 12 y          19x + 19y = 100 + 12y         19x + 7y - 100 = 0

19x - 399y - 912 = 0

19x + 7y - 100 = 0            406y = -812        y = -2

x - 21*(-2) - 48 = 0

x + 42 - 48 = 0

x - 6 = 0

x = 6

Пошаговое объяснение:

Надеюсь понятно.

Answer 2

To solve this system of linear equations, you can use the method of your choice, such as substitution or elimination. I'll use the elimination method in this example:

Given equations:

1. 21(x - y) = 48 + 20x
2. 19(y + x) = 100 + 12y

First, distribute on both sides to expand the equations:

1. 21x - 21y = 48 + 20x
2. 19y + 19x = 100 + 12y

Now, you can simplify these equations by moving like terms to one side:

1. 21x - 21y - 20x = 48
2. 19y - 12y + 19x - 19x = 100

Simplify further:

1. x - 21y = 48
2. 7y = 100

Now, isolate y in equation (2):

2. 7y = 100 Divide both sides by 7 to solve for y: y = 100 / 7 y = 14.2857 (rounded to 4 decimal places)

Now that you have found the value of y, you can substitute it back into equation (1) to find the value of x:

1. x - 21(14.2857) = 48 x - 300 = 48

Add 300 to both sides:

x = 48 + 300 x = 348

So, the solution to the system of equations is: x = 348 y = 14.2857 (or approximately 14.29 when rounded to two decimal places)