Percent Change = New Value − Old Value|Old Value| × 100%
Example: There were 200 customers yesterday, and 240 today:
240 − 200|200|× 100% = 40200 × 100% = 20%
A 20% increase.
Percent Error = |Approximate Value − Exact Value||Exact Value| × 100%
Example: I thought 70 people would turn up to the concert, but in fact 80 did!
|70 − 80||80| × 100% = 1080 × 100% = 12.5%
I was in error by 12.5%
(Without using the absolute value, the error is −12.5%, meaning I under-estimated the value)
The difference between the two is that one states factual calculations and the other is a theoretical guess
A regular trapezoid is shown in the picture attached.
We know that:
DC = minor base = 4
AB = major base = 7
AD = BC = lateral sides or legs = 5
Since the two legs have the same length, the trapezoid is isosceles and we can calculate AH by the formula:
AH = (AB - DC) ÷ 2
= (7 - 5) ÷ 2
= 2 ÷ 2
= 1
Now, we can apply the Pythagorean theorem in order to calculate DH:
DH = √(AD² - AH²)
= √(5² - 1²)
= √(25 - 1)
= √24
= 2√6
Last, we have all the information needed in order to calculate the area by the formula:

A = (7 + 5) × 2√6 ÷ 2
= 12√6
The area of the regular trapezoid is
12√6 square units.
Answer:
y =
+ 
Step-by-step explanation:
y''- 9 y' + 18 y = t²
solution of ordinary differential equation
using characteristics equation
m² - 9 m + 18 = 0
m² - 3 m - 6 m+ 18 = 0
(m-3)(m-6) = 0
m = 3,6
C.F. = 
now calculating P.I.


hence the complete solution
y = C.F. + P.I.
y =
+ 
Answer:
letter C is the right answer