Question

sistema de equação com passo a passo,por favor:
x-y=2
x²+y²+y=11

Answer 1

X-Y=2
X=2+Y

X²+Y²+Y=11
(2+Y)²+Y²+Y=11
4+4Y+Y²+Y²+Y-11=0
2Y²+5Y-7=0

D = 5² - 4 x 2 x -7
D = 25 + 56
D = 81

Y = -5 +- V81 / 2 x 2
Y = -5 +- 9 / 4
Y¹ =  - 5 + 9 / 4 = 4 / 4 = 1
Y² = - 5 - 9 / 4 = -14 / 4 = - 7 / 2

X¹ = 2 + 1 = 3
X² = 2 + (-7/2) = (4 / 2) - (7/2) = - 3 / 2 

S = {(3,1);(-3/2,-7/2)}