根据题意有:
x1+x2=3/2;
x1x2=-5/2;
2x2²-3x2-5=0;
2x2²-3x2=5;
∴x1²+x2²=(x1+x2)²-2x1x2=9/4+5=29/4;
∴(3)=x1²+3x2²-3x2
=x1²+x2²+2x2²-3x2
=29/4+5
=49/4;
很高兴为您解答,skyhunter002为您答疑解惑
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根据题意有:
x1+x2=3/2;
x1x2=-5/2;
2x2²-3x2-5=0;
2x2²-3x2=5;
∴x1²+x2²=(x1+x2)²-2x1x2=9/4+5=29/4;
∴(3)=x1²+3x2²-3x2
=x1²+x2²+2x2²-3x2
=29/4+5
=49/4;
很高兴为您解答,skyhunter002为您答疑解惑
如果本题有什么不明白可以追问,