Question

a posicao relativa y+x-7=0 2x-2y-1=0

Answer 1

Bom dia 

x + y - 7 = 0
2x - 2y - 1 = 0

y = -x + 7
m1 = -1

2y = 2x - 1
y = x - 1/2
m2 = 1

m1*m2 = -1*1 = -1

as retas são perpendiculares