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If a²+b²+c²=90 abd a+b+c=20 theb the calue pf ab+bc+ca |
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Answer» (a+b+c)² = a²+b²+c²+2(ac+bc+ca) (20)² = 90+2(ab+bc+ca) 400 = 90+ 2(ab+bc+ca) 400-90 =2(ab+bc+ca) 310 = 2(ab+bc+ca) .ab+bc+ca = 155 Step-by-step explanation: |
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