Top answers

When do you use 'n choose k' and where does the formula come from?

When do you use n choose k ? Say you have n objects/elements, and each one can either be selected or not selected. ‘ n choose k ’ gives you the number of different ways in which you can end up with k selecte...
TB
Answered by Tom B. • Maths tutor
21614 Views

Find the mean, median, mode and range of this data: 2, 5,6,12,5

To find the mean you must add all of the numbers together (2+5+6+12+5) and divide by how many numbers you have in your data set (5). Mean = 30 : 5 = 6 To find the median you must first order your numbers fro...
JT
Answered by Jonathan T. • Maths tutor
11049 Views

How do I factorise 3xy^2 – 6xy fully?

When we factorise, we do so to make the expression more simple. Factorising is when we take common factors from the expression and group them together, and then multiply these common factors by something to ...
MH
Answered by Matthew H. • Maths tutor
37424 Views

The polynomial p(x) is given: p(x)=x^3+2x^2-5x-6, express p(x) as the product of three linear factors

p(x)=x 3 +2x 2 -5x-6 =x(x 2 +2x-5)-6 =x(x 2 +2x+1-6)-6 as we know (x+1) 2 =x 2 +2x+1,5 can be expressed 1-6 =x[(x+1) 2 -6]-6 =x(x+1) 2 -6x-6 =x(x+1) 2 -6(x+1) =(x+1)[x(x+1)-6] =(x+1)(x 2 +x-6) here, -6 can b...
JB
Answered by Jingyi B. • Maths tutor
15320 Views

Factorise X^2 + 1X -12

Because the highest power of X is 2, this is a Quadratic Equation When factorised, these look like (x + a)(x + b) where a & b are constants To factorise this, we need to find 2 numbers which add together...
JW
Answered by Jack W. • Maths tutor
5888 Views