The Total solution for NCERT class 6-12
a2┬а+b2┬а+ c2┬а= 20, a + b + c = 0тИ┤ (a + b+ c)2┬а= 0a2┬а+ b2┬а+ c2┬а+ 2(ab + bc + ca)= 0тЗТ┬а20 + 2(ab + be + ca) = 0тЗТ┬а2(ab + bc + ca) = -20ab + bc + ca =┬атИТ202┬а=-10