Question

If a+b+c=9 and a^2+b^2+c^2=35 Then the value of ab+bc+ca=​

Answer 1

Step-by-step explanation:

Which of tire following are not ionic compounds

Answer 2

Answer:

23

Step-by-step explanation:

$a + b + c = 9 \\ {a }^{2} + {b}^{2} + {c}^{2} = 35 \\ {(a + b + c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2ab +2bc + 2ca \\ {(9)}^{2} = 35 + 2ab + 2bc + 2ca \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: (a + b + c = 9) \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: ({a}^{2} + {b}^{2} + {c}^{2} = 35) \\ 81 = 35 + 2(ab + bc + ca) \\ 81 - 35 = 2(ab + bc + ca) \\ 46 = 2(ab + bc + ca) \\ \: ab + bc + ca = 46 \div 3 \\ ab + bc + ca = 23$