Question

Obtenha o ponto de interseção entre as retas de equações: a) 2x +y -8 =0 e x +y -4 =0
b) x +y -10 =0 e 3x +y -14 =0

Answer 1

a) 2x+y-8=0
x+y-4=0

2x+y-8=0
y=8-2x

x+y-4=0
x+8-2x-4=0
-x+4=0
x=4

2x+y-8=0
2.4+y-8=0
8+y-8=0
y=0

P=(4,0)

b) x+y-10=0
3x+y-14=0

x+y-10=0
x=10-y

3x+y-14=0
3.(10-y)+y-14=0
30-3y+y-14=0
16-2y=0
2y=16
y=16/2
y=8

x+y-10=0
x+8-10=0
x-2=0
x=2

P=(8,2)