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Find the roots of the equation: x^2-2x-3=0

The point at which the explanation of the solution is started, will depend on the level of understanding of the student and previous knowledge on the subject A root is a numerical value that represents the s...
AP
Answered by Andreas P. • Maths tutor
7433 Views

How does oxygen enter the body?

Breathe in, you can feel your chest expanding and your body lifting up. When you breathe in, oxygen in the air around us moves into our lungs. The air moves through tubes called bronchi which branch, like a ...
GS
Answered by Georgia S. • Biology tutor
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Simplyfy, ((x-2)(x^2+5x+6)-(2x^2+10x+12))/(x^2+x-2)

The key to this is to not expand everything out and try work it out through that process. The easiest way is to notice that (x^2+5x+6) = (x+2), (2x^2+10x+12)=2(x+3)(x+2) and (x^2+x-2)= (x+2)(x-1).From this w...
TL
Answered by Thomas L. • Maths tutor
3276 Views

In aqueous solution, sulphuric acid dissociates into ions in 2 stages. The pKa for the first dissociation is -3. Calculate the pH of a 0.025 mol dm-3 solution of sulphuric acid using the pKa value of the 1st dissociation.

Ka = 10 -pKa = 10 --3 = 1000[H + ] = √ Ka [0.025] = √1000 x 0.025 = 0.791pH = -log [H] = -log(0.791) = 0.102 = 0.1
OM
Answered by Octavia M. • Chemistry tutor
3924 Views

How do I conjugate a present tense verb ending in er?

Firstly when a verb is not conjugated (ie. to go rather than I go ) , this is known as the infinitive . In french an example could be AIMER meaning to like . To conjugate a regular -er verb, you take off the...
MH
Answered by Matthew H. • French tutor
2263 Views