Step-by-step explanation:
x+3x+90=360
4x=360-90
x=270/4
x=67.5
We'll first simplify both sides of the expression to get (simply using the distributive property):

Then, we can simplify a little bit:

To solve for n, we have to isolate it. Let's subtract 3n from both sides to further simplify it:

Then, add 18 to both sides to get the value of n:

And that's your answer. If you have questions on how I got that, feel free to ask!
Im not entirely sure but, if you're on plato answer D is correct
model 1 has a random pattern and is fit for the data
Jo makes 170 minutes call. There are 150 free ones
170 - 150 = 20
20 minutes are "what Jo has to pay"
Jo sends 182 texts. There are 150 free ones
182 - 150 = 32
32 texts are "what Jo has to pay"
Monthly charge = 16p, 13p for each extra minute, 15p for each extra text.
13(20) = 260p
15(32) = 480p
480p + 260p + 16 = 740p + 16
740p + 16 is your answer (if p = pounds, add 16 to it, i'm not sure what p stands for though. If it is cents, divide 100 from 740 and take out the p, then add total to 16 to get answer.)
hope this helps
Another way to group the factors would be 3x(2x5)
The product would be 30
hope this helps..:)