Top answers

Please Simplify: (2x^2+3x/(2x+3)(x-2))-(6/x^2-x-2))

Factorise both parts of the question. Our left side would become x(2x+3)/(2x+3)(x-2) and our right side would become 6/(x+1)(x-2). On our LHS the (2x+3) would cancel leaving x/x-2. In order to merge the frac...
OG
Answered by Omar G. • Maths tutor
7309 Views

What are buffers and how do they work?

Buffers are solutions of acid and base which work to minimise changes in pH following the addition of small amounts of acid or base. Ideal buffers are made of a weak acid (i.e. one which does not fully disso...
SJ
Answered by Samuel J. • Chemistry tutor
8514 Views

Which compound has a higher boiling point and why: water (H2O) or methane (CH4)?

Water has a higher boiling point because the hydrogen bonds that form among water molecules are stronger than the Van der Waals interactions among methane molecules, thus more energy must be provided in orde...
MD
Answered by Maria D. • Chemistry tutor
43488 Views

How do you find (and simplify) an expression, in terms of n, for the sum of the first n terms of the series 5 + 8 + 11 + 14 + ... ?

Normally, this would be quite hard! We'd have to play around with the sequence and try different formulas until something worked. Luckily, this is what we call an "Arithmetic Series". That's becaus...
MS
Answered by Matthew S. • Maths tutor
19704 Views

How do you find the maximum and minimum value of a quadratic function with no use of calculus?

By completing the square, since this makes you see that the square will always be >= 0 and the other part allows you to calculate the minima or maxima depending on the sign in front of x 2 . E.g. x 2 +4x=...
AO
Answered by Alexander O. • Maths tutor
10462 Views