解不等式2小于等于x平方减7x+2小于10

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解不等式2小于等于x平方减7x+2小于10
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解不等式2小于等于x平方减7x+2小于10
解不等式2小于等于x平方减7x+2小于10

解不等式2小于等于x平方减7x+2小于10
解左边得:x>=7或x

-1小于等于x<8

2<=x^2-7x+2<10
2<=x^2-7x+2 x<=0或x>=7
x^2-7x+2<10 -1二者取交集:-1

2≤x^2-7x+2<10
0≤x^2-7x<8
即x^2-7x≥0,x>7,或x≤0
且x^2-7x<8,x^2-7x-8<0,解得-1<x<8
即-1<x≤0,7<x<8

2<=x^2-7x+2<10
2<=(x-7/2)^2-41/4<10
49/4<=(x-7/2)^2<81/4
7/2<=(x-7/2)<9/2 或 -7/2>=(x-7/2)>-9/2
7<=x<8 或 0>=x>-1