Question

Which is the equation of the line passing through the points A(3, -3) and B(-4, 11)?
Question 4 options:

y = -6x + 3

y = -2x + 3

y = 9x -3

y = 4x - 9

Answer 1

y=mx+c
First find the gradient using this formula\[m=\frac{ y_2-y_1 }{ x_2-x_1 }\]

Answer 2

\[A(3,-3)=A(x_1,y_1)\]\[B(-4,11)=B(x_2,y_2)\]

Answer 3

\[m=\frac{ 11-(-3) }{ -4-3 }\]\[m=\frac{ 11+3 }{ -7 }\]\[m=\frac{ 14 }{ -7 }\]\[m=-2\]

Answer 4

Now insert m=-2 into this equation y=mx+c

Answer 5

oh, sorry i was trying to figure it out in my head, plus i hate fractions.

Answer 6

-2=mx+3?

Answer 7

wait no

Answer 8

y = -2x + 3

Answer 9

y=mx+c
where
y=vertical axis
x=horizontal axis
m=gradient of the straight line
c=constant or y-intercept

Answer 10

yup :)

Answer 11

k thx

Answer 12

u can choose either coordinate A or coordinate B to substitute the value of x and the value of y in this equation :y=mx+c

Answer 13

let's say we choose coordinate A(3,-3)=A(x,y)\[y=-2x+c\]\[-3=-2(3)+c\]\[c=3\]\[Therefore,y=-2x+3\]

Answer 14

you're welcome :)