They have 310 stickers in total
Lets get all the information we need first.
A week has 7 days, you practice 30 min each day, so in a week you will practice a total time t of 30 min for 7 times, that is:
t = 7day(30 min/day)
t = 210 min
So in a week you will practice a total of 210 minutes.
Answer: 16
Step-by-step explanation:
The answer to this problem is x<-4
Given

To find a solution for the linear equation, the first step is to write the equation in slope-intercept form:
-Pass the x-term to the right side of the equation by applying the opposite operation to both sides of the equal sign:

-Divide both sides by -2:

Once you have expressed the equation of the line in slope-intercept form, replace it with any value for x and calculate the corresponding value of y, for example, x=2

One solution for the linear equation is x=2 and y=-6, you can check the solution by replacing the values on the original equation, with both values the result should be 8:

As you can see the values are a valid solution for the linear equation.
So the solution is: