Question

(SAEPI).A reta t passa pelos pontos (4, 8) e

(2, ‒ 6).Qual é a equação da reta t?

A) y = 7x – 20

B) y = 7x – 52

C) y = 6x + 2

D) y = 4x + 8

E) y = 2x – 6​

Answer 1

cálculo do coeficiente angular da reta t:

$\mathtt{m=\dfrac{-6-8}{2-4}}\\\mathtt{m=\dfrac{-14}{-2}}\\\mathtt{m=7}$

Equação da reta na forma ponto coeficiente-angular

$\huge\boxed{\boxed{\mathtt{y=y_{0}+m(x-x_{0})}}}$

$\mathsf{x_{0}~e~y_{0}~~s\tilde{a}o~~os~~coordenadas~~do~~ponto~~escolhido}$

adotando o ponto (4,8) temos

$\mathtt{y=8+7(x-4)}\\\mathtt{y=8+7x-28}\\\huge\boxed{\boxed{\mathtt{y=7x-20}}}$

$\huge\boxed{\boxed{\mathtt{\maltese~~Alternativa~~A}}}$