What is the sum of the infinite series?

What is the sum of their area? what is the sum of 4 and 1 the tenth term of an arithmetic series is 67 and the sum o 原题：What is the present value of an infinite set of cash flow what is the sum of the first five prime numbers The sum of 130 and X is 250,what is The sum of two even numbers is always what? 一个英语数学题What is the value of the sum of a sequence of x conse .What is the minimum value of the sum of a positive real num what is the sum of the roots of 4x+3x-8=0? What is the greatest of 5 consecutive integers if the sum of :the sum of 14 consecutive integers is 217,what is the sixth