Question

{2x+11y=15. {10х-11у=9

Answer 1

  2x+11y=15              11y=15-2x                   

{                       =>     {

  10x-11y=9                10x-(15-2x)=9                11y=15-2*2

                                       10x-15+2x=9                 y=1

                                       12x=24

                                         x=2 

Answer 2

{2x+11y=15
{10х-11у=9  складываем их. Возле середины скобки сбоку ставим знак +. При сложении получаем 2х + 10х= 24. отсюда 12х=24. х=2. 
Когда ты складывала y-ки у  тебя сократились( 11у + (-11у))=0 получилось. Надеюсь я понятно объяснила)))
 

Answer 3

To solve this system of equations using the elimination method, we need to eliminate one of the variables. In this case, we can eliminate y by multiplying the first equation by 10 and the second equation by 11, then subtracting the second equation from the first:

20x + 110y = 150
110x - 121y = 99
-------------------
-90x + 231y = 51

Now we have an equation in terms of only y, which we can solve for:

231y = 90x + 51
y = (90/231)x + 51/231

Substituting this value of y into either of the original equations, we can solve for x:

2x + 11[(90/231)x + 51/231] = 15
2x + (990/231)x + (561/231) = 15
(297/231)x = (15 - 561/231)
(297/231)x = (344/231)
x = (344/231) * (231/297)
x = (344/297)

Now that we have x, we can use either of the original equations to solve for y:

10x - 11y = 9
10(344/297) - 11y = 9
(3440/297) - (11/1)y = (9/1)
(-11/1)y = (9/1) - (3440/297)
(-11/1)y = (-2369/297)
y = (2369/297) * (-1/11)
y = (-2369/3247)

Therefore, the solution to the system of equations is x = (344/297) and y = (-2369/3247).