Question

please solve one by one.​

Answer 1

Step-by-step explanation:

Q. (1)

ans:- a+b-c = 3

वर्ग करने पर

(a+b-c)²=9

a²+b²+c²+2ab-2bc-2ac = 9

चूँकि a²+b²+c²=77

अत: 77+2(ab-bc-ac) = 9

2(ab-bc-ac) = -68

ab-bc-ac = -34