Blind company A charges $25.00 to install blinds for one room and $5.00 for each additional window. Blind company B charges $30.00 to install
blinds in one room and $4.00 for each additional window. Write an
equation to determine how many additional windows would need to be
installed for the price to be the same at both companies?

4

Step-by-step explanation:

You can plug in the b's and see.  You can also try to use a co-function identity and get a value for b that way.

Let's try the co-function identity:

sin(x)=cos(90-x).

First step:

cos(11b+2)=cos(90-[12b-4])

 So one set of solutions can be found by solving:

11b+2=90-[12b-4]

Distribute:

11b+2=90-12b+4

Add 12b on both sides

23b+2=90+4

Simplify:

23b+2=94

Subtract 2 on both sides:

23b     =94-2

23b      =92

Divide both sides by 23:

  b=       92/23

  b=        4

So 4 is one value that will work.