Q) Is x < 0 ?
1) -4x < 0
2) -4x^2 < 0
What I want to know is
1) -4x < 0 ; either 4 is negative or x is negative. Hence cant say if x <0.
But explanation for this is given that
dividing both sides by -4, we get x > 0. Hence we know that x > 0.
Can anyone please help me understand why -4x is not 4 * (-x)? and in case it is 4*(-x) then why cant x<0 ?
2) Is clear to me. Hence no questions
if x < 0, let say, x=-1, then (-4)(-1)>0
which contrary to the given inequality.
again, if x>0, let say, x=2, then (-4)(2)<0
Thus, we can say x>0
Let me know if you need any further clarification,
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