Answer : The equation could you use to find p is, 
Step-by-step explanation :
Let the cost of 1 pen be, 'x'
and the cost of 1 pencil is, 'p'
As we are given that total cost of 1 pen and 1 pencil is $2.10. The equation will be:
............(1)
And we have also given that the pen costs twice as much as a pencil. The equation will be:
............(2)
Now put the equation 2 in equation 1, we get:


Thus, the equation could you use to find p is, 
Answer:
8,640
Step-by-step explanation:
EASY PERIOD
<h2>
Answer:</h2>
Each month, 2.8% Ramon's earnings are spent on electricity.
<h2>
Step-by-step explanation:</h2>
You know, that 100 percent are his earnings - $1,880
Now, you need to find out, how much is 1%. You do that by dividing $1,880 by 100.
Now you have to divide the amount he pays on electricity - $53.3 by one percent of his earnings - $18.8
So, now you know, that he pays exactly 2.83511% of his earnings on electricity. But from assignment, you know, that it has to be rounded to the nearest tenth of a percent. The number is 2.8351. So we will round it to 2.8% ,because 3 is rounded down. (https://www.mathsisfun.com/rounding-numbers.html)
100% = $1,880
$1,880/100 = $18.8
$53.3/$18.8 = 2.83511
2.83511% ≈ 2.8%