Question

4. If a + b + c = 12 and a2 + b2 + 2 = 50: find
ab + bc + ca.
5. If a2 + b2 + 2 = 35 and ab + bc + ca = 23:
find a + b + c
6. If a + b + c = p and ab + bc + ca = q;
find a2 + b2 + 2.
4.6 USING EXPANSIONS​

Answer 1

Step-by-step explanation:

(a+b+c)^2 - 2(ab+bc+ca) = a^2 + b^2 + c^2

1. ab+bc+ca = (12)^2 -50 / 2 = 94/2 = 47

2. (a+b+c)^2 = 35 + 46 = 81

a+b+c = 9

3. a^2 + b^2 + c^2 = p^2 - 2q