Question

Реши систему уравнений методом подстановки.
d) m² - mn = 5
m² + mn = - 1

e) 4m² - mn = 5
mn - m² = 7

f) x² + y² = 25
2x² + y² = 9

a) x² + y² = 37
x - y = 5

b) - 2ab = 9
2b +3a = 6

c) m²+16n² = 16
m+2 = 2n

Answer 1

1) {x=y+2
{3*(y+2)-2y=9
3y+6-2y=9
y=3.
x=3+2=5.
2) y=x+1
5x+2y=16
5x+2*(x+1)=16
5x+2x+2=16
7x=14
x=2
y=2+1=3.