1){x-y=5 {x^2+5x=0 2){x^2+y^2=26 {x-y=-4 3){x+y=7 {y^2-3y=0напишите только решение без...

Question

1){x-y=5
{x^2+5x=0
2){x^2+y^2=26
{x-y=-4
3){x+y=7
{y^2-3y=0
напишите только решение без слов

Answer 1

1) {x - y = 5, x^2 + 5x = 0}
x(x +5) = 0
x = 0, y = -5
x = -5, y = -10
2) {x^2 + y^2 = 26, x - y = -4}
y = x + 4
x^2 + (x+4)^2 = 26
2x^2 + 8x + 16 = 26
x^2 + 4x - 5 = 0
x = -5, y = -1
x = 1, y = 5
3) {x+y = 7, y^2 - 3y = 0}
y(y-3) = 0
y = 0, x = 7
y = 3, x = 4