Question

number of integral values of X satisfying (x+3)(x-20) < 0

Answer 1

ANSWER

−x  

2

+10x−16

​  

<x−2

∴−x  

2

+10x−16≥0

x  

2

−10x+16≤0

(x−2)(x−8)≤0

x∈[2,8]…(1)

−x  

2

+10x−16

​  

<x−2

squaringonbothsides

−x  

2

+10x−16<x  

2

−4x+4

2x  

2

−14x+20>0

x  

2

−7x+10>0

(x−5)(x−2)>0

x∈(−∞,2)U(5,∞)…(2)

Points which lie in both the interval (1) and (2) are 6,7 and 8

∴x=6,7,8

so3valuesofx