result? A.8. What do the following stand for? 4 a. e. E (i + 4) 6 3 b . Lay; a is a constant E3 1= 2 i=1 2 10 C. E ( 2xi + 3yi) 8. 3 3 d. Exiyi h. E ( 4x2 - 3) = 1 A.9. Express the following in the _ notation: a. X1 + x2 + x3 + x4+ x5 b. x1 + 2x2 + 3x3 + 4x4 + 5x5 c. ( x7 + 19) + ( x3 + 13) +... + (x7 + yk)