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If X y and z are four consecutive term of an a.p then find X and y in term of b and c |
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Answer» ANSWER Let the TERMS be a−3d,a−d,a+d,a+3d. Given, Sum =20 ⇒a−3d+a−d+a+d+a+3d=20 ⇒4a=20 ⇒a=5 Also given, sum of squares =120 ⇒(a−3d) +(a−d) 2 +(a+d) 2 +(a+3d) 2 =120 ⇒(5−3d) 2 +(5−d) 2 +(5+d) 2 +(5+3d) 2 =120 ⇒25−30d+9d2+25−10d+d 2 +25+10d+d 2
⇒25+30d+9d 2 =120 ⇒100+20d 2 =120 ⇒20d 2 =20 ⇒d 2 =1 ⇒d=±1 The terms are a−3d,a−d,a+d,a+3d Thus, 5−3,5−1,5+1,5+3 (i.e.) 2,4,6,8 or 8,6,4,2 Step-by-step explanation: please follow me |
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