Question

Help me with y=mx + b problems, step by step

Answer 1

So you know what the general equation for a line is

\(y=mx+b\)
m is the rate
b is the starting point

Answer 2

What is the original water level of the river?

Answer 3

y = 0.5x + 34

Answer 4

Close, if it is receding it is going down

Answer 5

so y = 0.5x - 34?

Answer 6

Not quite, the rate is negative, not the water level xD

Answer 7

y= -0.5x + 34

Answer 8

Yes, that is the equation for this situation

Answer 9

alright

Answer 10

If you want to find the days at which it reaches 26 feet, substitute it for y (or L in this case)

\(26=-0.5x+34\)

Answer 11

ok

Answer 12

Solve for x to get the number of days

Answer 13

i got -86

Answer 14

LOL

Answer 15

Uhh you mixed up signs along the way LOL

It should be 16, not -16

Answer 16

ooh ya i got 16 now

Answer 17

someone told me that i should always divide for example (-0.5) with every thing

Answer 18

Oh you probably want to get rid of the fraction?

Answer 19

oh it turns out i do divide it to all the numbers, this part always confuses me

Answer 20

\(26=-0.5x+34\)
(Make 0.5 a fraction)

\(26=-\frac{1}{2}x+34\)
Your friend probably meant to multiply everything by -2 to get rid of the fraction (and negative in this case)
\(\color{red}{-2(}26=-\frac{1}{2}x+34\color{red}{)}\)

=>\(-52=x-68\)
Add 68 on both sides
\(-52\color{red}{+68}=x-68\color{red}{+68}\)
\(\color{red}{+}16=x\)

Answer 21

oh idk about that

Answer 22

I did the same thing your friend told you, dividing by 0.5 is the same as multiplying 2

Answer 23

So i did it like this,

26 = -0.5x + 34
/-0.5 /-0.5 /-0.5
-52 = x + -68
-68 -(-68)
16 = x

Answer 24

Yes, that is the same thing I did, just in a more visual appealing way imo
¯\_(ツ)_/¯

If that seems more comfortable with you, then do it

Answer 25

oh alright B)

Answer 26

Can we do more problems?

Answer 27

Sure, make a new post