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## #1 Help Me ! » Number Properties » 2013-08-02 01:53:15

math.guru.92
Replies: 2

Having problems solving this question.

## #2 Re: Computer Math » The two trains » 2013-07-25 23:08:28

this problem can be solved using the equation:
s=vt
here s=140+160=300m
v=40+60=100km/h
first we convert velocity into meters per second
so we get v=(10*1000)/3600
now using t=s/v
we get t=10.8 seconds

## #3 Re: Help Me ! » Why is the square root of (x+y)^2 not (-x-y)? » 2013-07-25 22:50:51

It is simple. Here we are dealing with the polynomial of degree "2" so when we will take a an under root on both sides, we will find two solutions of x one with a positive sign and one with negative sign.
(x+3)^2 = 13  ---------- original
when we take under root we get two equations
(x+3) = +√13 ----(equation 1)                                 (x+3) = -√13 ------- (equation 2)
equation 1 goes to form                                           equation 2 goes to form
x=+√13 - 3                                                                x=-√13 -3