Question

determine a equação da reta q passa pelos pontos A(-3,2) e (5,-4)

Answer 1

Y = ax+b

a = Δy/Δx

a = (-4-2)/(5-(-3))

a = -6/8

a = -3/4
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Y = -3/4*x + b

Y = -3x/4 + b

Substitue qualquer ponto. A ou B

A(-3, 2)

Y = -3x/4 + b

2 = -3*-3/4 + b

2 = 9/4 + b

b = 2 - 9/4

b = 8/4 -9/4

b = (8-9)/4

b = -1/4
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Y = -3x/4+b

Y = -3x/4 -1/4

Answer 2

$m = \frac{Delta x}{Deltay}= \frac{-4-2}{5-(-3)}$ $=- \frac{6}{8}$ $= -\frac{3}{4}$

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$y-y0=m(x-x0)$
$y-2= -\frac{3}{4} (x-(-3))$
$y-2= -\frac{3}{4} (x+3)$
$y-2=- \frac{3}{4}x- \frac{9}{4}$
$y=- \frac{3}{4}x- \frac{9}{4} +2$
$y=- \frac{3}{4}x- \frac{9}{4} + \frac{8}{4}$
$y=- \frac{3}{4}x- \frac{1}{4}$
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Espero ter ajudado!