In the first series, the summation applies to the whole (2n+3) inside
the parentheses, so the 3 gets summed up 5 times.
But in the second one, the summation only applies to the 2n , so
the 3 is only added after the summation is finished.
The difference between five 3s the first time and one 3 the second time
is your 12 .
Answer:
x = 6
Step-by-step explanation:
Let x = first number
x+4x = 30
5x = 30
Divide by 5
5x/5 =30/5
x = 6
Answer: 67.27
Step-by-step explanation:
7.1 x 7.1 for the square = 50.41
7.1 divided by 2 = 3.55
3.55 x 4.75= 16.86
Normally here you would divide by 2, but you don’t need two because there is 2 triangles that are the same
Add the 50.41 and the 16.86 and you have your answer!