Question

pls help me this three urgent​

Answer 1

Answer:

(1) 29

Step-by-step explanation:

$({a + b + c })^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2(ab + bc + ac) \\ {9}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2(26) \\ {a}^{2} + {b}^{2} + {c}^{2} = 81 - 52 = 29$