Solve the summation from n equals 2 to 10 of negative 4 plus 5 times n.
189
234
235
286

The summation from n equals 2 to 10 of negative 4 plus 5 times n is 234

Solution:

Given that summation from n equals 2 to 10 of negative 4 plus 5 times n

We have to calculate the sum of the following:

∑( -4 + 5n ) for n = 2 to n = 10

Let us substitute for n = 2 to n = 10 and find the sum

∑( -4 + 5n ) = (-4 + 5(2)) + (-4 + 5(3)) + (-4 + 5(4)) + (-4 + 5(5)) + (-4 + 5(6)) + (-4 + 5(7)) + (-4 + 5(8)) + (-4 + 5(9)) + (-4 + 5(10))

∑( -4 + 5n ) = (9 x - 4) + 10 + 15 + 20 + 25 + 30 + 35 + 40 + 45 + 50

∑( -4 + 5n ) = -36 + 270

∑( -4 + 5n ) = 234

Thus the summation from n equals 2 to 10 of negative 4 plus 5 times n is 234

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!