Question

Write the equation of the line given the slope and the y-intercept.
m = 5, y-intercept (0, -3)

Answer 1

Use the fact that the equation of any line in slope intercept form is y = mx+b

Answer 2

So if say the slope was 17 and the y-intercept was (0,8), then

y = mx+b

y = 17x + b

y = 17x + 8

This is NOT the answer as it's just an example

Answer 3

y=5x+-3 ?

Answer 4

good, and that simplifies to y = 5x - 3

Answer 5

I should have pointed out that m is the slope and b is the y-intercept (which is the point (0,b))

But I'm sure you've already figured that part out by now

Answer 6

So then my answer would be y=5x-3 ?

Answer 7

yes correct

Answer 8

Wow, that makes sense. Thanks @jim_thompson5910 !

Answer 9

glad to be of help

Answer 10

@jim_thompson5910 I also have a similar problem if you could help....

Answer 11

Write the equation of the line given the slope and a point on the line. in slope-intercept form, m = -4, point (1, -3)

Answer 12

Would it be y=-4+-3 ?

Answer 13

no the trick used above only works if the point looks like (0, ???) where you replace the ??? with any number

Answer 14

So the trick works if the line goes through (0,6) or (0,19)....but does NOT work for (1,-3)

Answer 15

you have to do this

Answer 16

y = mx + b

y = -4x + b ... plug in m = -4

-3 = -4(1) + b .... plug in x = 1 and y = -3 (from the point (1,-3))

-3 = -4 + b ... multiply

I'll let you finish and solve for b

Answer 17

-3=-4+-3 ?

Answer 18

if you have

-3 = -4 + b

how would you isolate b

Answer 19

add four to both sides?

Answer 20

1=b ?

Answer 21

very good

Answer 22

b = 1

Answer 23

so m = -4 and b = 1

Answer 24

which means

y = mx+b

turns into

y = -4x + 1

Answer 25

OR you could always use the point slope formula.....(it simplifys to y=mx + b)

m = -4, point (1, -3)

y - y1 = m(x - x1)

you have a point...(1, -3)
and a slope (-4)

in this equation...m is slope

so

y - (-3) = -4(x - 1)
y + 3 = -4x + 4

finish that simplification :)