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How do I solve the simultaneous equations 2x - y = 3 and 3x + y = 9

First of all you need to spot a way we can add or subtract these two equations together so that we can get rid of one of the terms . This is easily spotted by writing the equations like so:2x - y = 13x + y =...
JB
Answered by Joshua B. • Maths tutor
6284 Views

How do you factorise a quadratic expression using the formula

To factorise an expression of the formax 2 +bx+c We use the formulaX=(-b+/- (b^2-4ac)^(1/2))/2aExample:Factorise 3X 2 +2X+-1So here a=3 b=2 c=-1From the formula we get X=1/3 and X=-1And so our factorisation ...
KS
Answered by Kaitrin S. • Maths tutor
3377 Views

Calculate y=4x-6 when x=3

Firstly we have an equation y=4x-6. We are given that x=3 and we want to find y. What we must do is substitute x=3 into the equation to get y: y=4(3)-6 =6
SU
Answered by Sinan U. • Maths tutor
4733 Views

Expand and simplify (3x^2 + 2)(2x + 5) – 6x(x^2 – 3)

First, multiply out 6x(x^2 - 3) so that it becomes – 6x^2 – 18xThen, multiply (3x^2 + 2) and (2x + 5) so that it becomes 6x^3 + 15x^2 + 4x + 10Add the two results above: 6x^3 + 15x^2 + 4x + 10 – 6x^3 – 18x S...
AB
Answered by Ancel B. • Maths tutor
9216 Views

How do you calculate the sum of all internal angles of a regular polygon?

Use the formula (n-2)*180 where n is the number of sides on the polygon.
BC
Answered by Ben C. • Maths tutor
3462 Views