Question

2S+3T-1=0 4S-9T-8=0 求ST……

Answer 1

2S+3T-1=0.(1)

4S-9T-8=0.(2)

(1)*2-(2),得

15T+6=0

15T=-6

T=-0.4

代入(1),得

2S+3*(-0.4)-1=0

2S-1.2-1=0

2S=2.2

S=1.1

所以

S=1.1,T=-0.4