Question

find five numbers in A. P. whose sum is 25 and the sum of whose square is 135​

Answer 1

Answer:

Thus, we get the following equation: (a−2d)2+(a−d)2+a2+(a+2d)2+(a+d)2=135. ⇒(5−2d)2+(5−d)2+25+(5+2d)2+(5+d)2=135 . ⇒25+4d2−20d+25+d2−2d2+25+25+4d2+20d+ .