Question

the first term of ap is 5,the last term is 45 and the sum is 400 . find the number of terms and the common difference.

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Answer 1

Answer:

no of terms : 16

common difference : 25/3

Step-by-step explanation:

sum = $\frac{n(a+l)}{2}$ =400

apply a and l in the equation

n(5+45)/2 = 400

       n(50) = 800

             n = 16

last term = 45 = a + (n-1)d

           45=5 +15d

            d=50/15 = 25/3  

Answer 2

Answer:

Given : 8(3a−2b)

2

−10(3a−2b)

By talking (3a−2b) in the given question, we get,

(3a−2b)[8(3a−2b)−10]

By taking 2 as common in the second term,

(3−2b)2[4(3a−2b)−5]

So we get,

8(3a−2b)

2

−10(3a−2b)=2(3a−2b)(12a−8b−5)

Step-by-step explanation:

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