Giưps to voi ạ!!!!!!

Đáp án`+`Giải thích các bước giải:

 `1, {(x -5y = 16),(-x + 3y = -10):}`

`<=> {(x = 16 + 5y),(-16- 5y +3y = -10):}`

`<=> {(x = 16 +5y),(-2y  = 6):}`

`<=> {(x = 16+ 5y),(y = -3):}`

`<=> {(x = 1),(y = -3):}`

Vậy `(x;y) = (1;-3)`

`2, {(2x+  y = 11),(3x- y  = 4):}`

`<=> {(y = 11 - 2x),(3x - 11 + 2x = 4):}`

`<=> {(y = 11 - 2x),(5x=  15):}`

`<=> {(y = 11 - 2x),(x = 3):}`

`<=> {(y = 5),(x = 3):}`

Vậy `(x;y) = (3;5)`

`3, {(3x+  2y = 5),(x - 2y = 1):}`

`<=> {(3x+  2y = 4),(x =1 + 2y):}`

`<=> {(3(1 + 2y) +2y = 4),(x = 1+ 2y):}`

`<=> {(3 + 6y + 2y = 4),(x = 1 + 2y):}`

`<=> {(8y = 1),(x = 1 + 2y):}`

`<=> {(y = 1/8),(x = 5/4):}`

Vậy `(x;y) = (5/4;1/8)`

`4, {(2x+ 3y = 2),(-2x + y = 12):}`

`<=> {(2x = 2 - 3y),(-2 + 3y +y = 12):}`

`<=> {(2x = 2 - 3y),(4y = 14):}`

`<=> {(2x = 2 - 3y),(y = 7/2):}`

`<=> {(x = (2 - 3. 7/2)/2),(y = 7/2):}`

`<=> {(x = (-17)/4),(y = 7/2):}`

Vậy `(x;y) = ((-17)/4;7/2)`

`5, {(-3x + 2y = -3),(3x-  4y = 5):}`

`<=> {(2y = -3 + 3x),(3x - 2(-3 + 3x) = 5):}`

`<=> {(2y = -3 + 3x),(3x + 6 - 6x = 5):}`

`<=> {(2y = -3 + 3x),(-3x = -1):}`

`<=> {(y = (-3 + 3x)/2),(x = 1/3):}`

`<=> {(y = -1),(x = 1/3):}`

Vậy `(x;y) = (1/3;-1)`

`6, {(2x + 3y = 2),(-2x +y = 12):}`

`<=> {(2x =2 - 3y),(-2 + 3y + y =12):}`

`<=> {(2x= 2 - 3y),(4y = 14):}`

`<=> {(x=  (2 - 3y)/2),(y = 7/2):}`

`<=> {(x =(-17)/4),(y=  7/2):}`

Vậy `(x;y) = ((-17)/4;7/2)`

`7, {(2x - 11y=  -7),(10x + 11y = 31):}`

`<=> {(11y = 2x + 7),(10x + 2x+  7 = 31):}`

`<=> {(11y = 2x+  7),(12x=  24):}`

`<=> {(y = (2x+  7)/(11)),(x = 2):}

`<=> {(y = 1),(x = 2):}`

Vậy `(x;y) = (2;1)`

`8, {(5x - 2y = 4),(3x + 2y = 12):}`

`<=> {(2y = 5x - 4),(3x + 5x - 4 = 12):}`

`<=> {(2y = 5x - 4),(8x = 16):}`

`<=> {(y = (5x-  4)/2),(x = 2):}`

`<=> {(y = 3),(x = 2):}`

Vậy `(x;y) = (2;3)`

`9, {(4x +7y = 16),(-4x+ 3y = 24):}`

`<=> {(4x=  16 - 7y),(-16 + 7y + 3y = 24):}`

`<=> {(4x = 16 - 7y),(10y = 40):}`

`<=> {(x = (16 - 7y)/4),(y = 4):}`

`<=> {(x = -3),(y = 4):}`

Vậy `(x;y) = (-3;4)`

`10, {(2x - 5y = -14),(2x+ 3y = 2):}`

`<=> {(2x = -14 + 5y),(-14 + 5y + 3y = 2):}`

`<=> {(2x = -14+ 5y),(8y = 16):}`

`<=> {(x = (-14 + 5y)/2),(y = 2):}`

`<=> {(x = -2),(y= 2):}`

Vậy `(x;y) = (-2;2)`

`11, {(2x + 5y = 7),(2x -3y = -1):}`

`<=> {(2x=  7 - 5y),(7 - 5y - 3y = -1):}`

`<=> {(2x=  7 - 5y),(8y = 8):}`

`<=> {(x =  (7 -5y)/2),(y = 1):}`

`<=> {(x = 1),(y = 1):}`

Vậy `(x;y) = (1;1)`

`12, {(-x + 3y = -10),(2x + 3y = -1):}`

`<=> {(x = 10 + 3y),(2(10 + 3y) + 3y = -1):}`

`<=> {(x = 10 + 3y),(20 + 6y + 3y = -1):}`

`<=> {(x = 10 + 3y),(9y = -21):}`

`<=> {(x = 10 + 3y),(y = (-7)/3):}`

`<=> {(x= 3),(y= (-7)/3):}`

Vậy `(x;y) = (3;(-7)/3)`

`***`sharksosad