83. (Og`zaki.) x=5 qiymat tengsizlikning yechimi bo`lishini ko`rsating:
1) (x–1)(x–3)>0; 2) (x+2)(x+5)>0;
3) (x–7)(x–10)>0; 4) (x+1)(x–4)>0.
Tengsizlikni intervallar usuli bilan yeching (84 – 90):
84. 1) (x+2)(x–7)>0; 2) (x+5)(x–8)>0;
3)
(x–2)(x+
)
4)
.
85. 1) x2+5x>0; 2) x2–9x>0; 3) 2x2–x<0;
4) x2+3x<0; 5) x2+x–12<0; 6) x2–2x–3>0.
86. 1) x3–16x<0; 2) 4x3–x>0;
3) (x2–1)(x+3)<0; 4) (x2–4)(x–5)>0.
87. 1) (x–5)2(x2–25)>0; 2) (x+7)2(x2–49)<0;
3) (x–3)(x2–9)<0; 4) (x–4)(x2–16)>0;
5) (x–8)(x–1)(x2–1)≥0; 6) (x–5)(x+2)(x2–4)≤0.
88.
1)
;
2)
;
3)
;
4)
;
5)
;
6)
.
89.
1)
2)
3)
4)
90. 1) (x2–5x+6)(x2–1)>0; 2) (x+2)(x2+x–12)>0;
3) (x2–7x+12)(x2–x+2)≤0; 4) (x2–3x–4)(x2–2x–15)≤0.
Tengsizlikni yeching (91 – 93):
91.
1)
2)
3)
4)
92.
1)
2)
93.
1)
2)
3)
4)
