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Solve these simultaneous equations: 3y + x = 18 and x - 4y = -10.

Write x in terms of y using one of the equations. Then substitute it in the second equation, which is then only in terms of y. Find y. Then you can easily find x.

Answer: x = 6 and y = 4.

Answered by Tess E. • Maths tutor

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How do you solve simultaneous equations?

The easiest way to solve simultaneous equations is by elimination. This is the idea of cancelling out one of your variables, the X or Y so that you can solve the remaining variable and then substitute thi...

Answered by Ben H. • Maths tutor

3919 Views

Expand (x+4)(x+3).

To answer this you multiply everything in the left bracket by everything in the right bracket, so rewrite the equation as x(x+3)+4(x+3). Then you can expand each more easily:

x(x+3) = x

Answered by Elliot D. • Maths tutor

31281 Views

How do I remember the trigonometry identities from C3 in the exam?

I often find it difficult to remember all the different identities, so what is useful is instead to just remember the familiar identity sin^2(x) + cos^2(x) = 1 that we have come across many times, and div...

Answered by Joshua S. • Maths tutor

4673 Views