Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
infact .. when u see x is < or> than the negetive number the sign get changed .. imean in this case.. if x >-2 then it gets -2<x<7....then its not true to say x>2 st choice is wrong.. _________________
if it is true that x> -2 and x>7 ,which of the following must be ture?
Now the values of x that will always satisfy above 2 inequalities will be:
x > 7.
Seems like choices are messed up.
Tips on inequalities (basics):
1) Multiply an inequality by a negative number and sign of inequality changes, for eg:
x < -2
or -x > 2 (multiply both sides by -1)
2) If two set of numbers a,b & x,y are positive
and x*a > y*b such that x < y
then a > b ( i remember seeing one question that tested this)
3*x^2 > 4*y^2 (here x^2, y^2 are positive numbers -squares)
Then, X^2 > Y^2
whereas, if 4*x^2 > 3*y^2
Then, i cannot conclude anything..!!
If X, Y are average of two sets of data then X, Y are always positive.
3) Mutiplying by a positive number, adding or subtracting any number (positive or negative) [u]does't change the sign of inequality.[/u]For example:
3 > -5 -----------a
then 9 > -15 (3 mutiplied on both sides of eq a)
Also, 0 > -8 (3 subtracted from both sides of eq a)
Also, 6>-2 (3 added on both sides of eq a)