Answer:
10cm
Step-by-step explanation:
The formula for perimeter is:

Let the width of the rectangle be x then the length would be...
3+x
Now, let's plug these values into the equation and solve. (Note we are also given perimeter is 34 cm):

And since the length is x+3 then it is...
x+3=7+3=10cm
Answer: 23
Step-by-step explanation:
For the first one it is 4n^2-4
Answer: Option D
D. 880 = 45d + 70; 18 days
Step-by-step explanation:
We know that the cost of preschool is $ 45 per day plus a monthly fee of $ 70.
We also know that a total of $ 880 was paid last month
To write an equation that represents this situation, let us call d the number of days that Barry attends school
So the cost was:

Now we solve the equation for the variable d




The answer is the option D