Question

esboce o gráfico de duas retas q passem pelos pontos r:A(4,0) e B(0,-3) s:C(-2,0) e D(0,4).
E´ possivel dizer se as retas se interceptam ou sao paralelas?

Answer 1

Oi Lilian

reta r: A(4,0) , B(0,-3)

f(x) = ax + b

f(4) = 4a + b = 0
f(0) = b = -3

4a - 3 = 0
4a = 3
a = 3/4 

f(x) = (3x - 12)/4 

reta s: C(-2,0), D(0,4) 

g(x) = ax + b

g(-2) = -2a + b = 0
g(0) = b = 4

-2a + 4 = 0
2a = 4
a = 2

g(x) = 2x + 4 

(3x - 12)/4 = 2x + 4

3x - 12 = 8x + 16
8x - 3x = -12 - 16

5x = -28 
x = -28/5 

y = 2x + 4 
y = -56/5 + 20/5 = -36/5 

as retas se interceptam no ponto P(-28/5, -36/5)