The 9th term of an arithmetic progression is 8 and the 4th term is 18.
find the 1st term and the common difference, d.

a = 24 and d = -2

Step-by-step explanation:

The 9th term = a + 8d

the 4th term = a + 3d

from the question it is given that

a + 8d = 8(1)

a + 3d = 18(2)

Solve the two equations simultaneously we will be a = 24 and d = -2

2500

step-by-step explanation:

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )