Question

解方程组a+b+c=0 4a+2b+c=3 25a+5b+c=60

Answer 1

a+b+c=0 (1)

4a+2b+c=3 (2)

25a+5b+c=60 (3)

(2)-(1)

3a+b=3 (4)

(3)-(1)

24a+4b=60,6a+b=15 (5)

(5)-(4)

3a=12

a=4

b=-9

c=5