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Solve the simultaneous equations: 4x + y = 25, x - 3y = 16

We need to have either the same number of x's or the same number of y's in each equation so that we can add or subtract them to be left with just x or just y. We can do this by multiplying the second equatio...
LH
Answered by Lydia H. • Maths tutor
35116 Views

Prove that 0.565656.... can be expressed as 56/99.

1) Let x=0.565656... 2) Thus 100x=56.565656... 3) Subtracting equation 1) from 2) gives: 99x=56 4) Rearrange for x: x=56/99, Also x=0.565656... from 1) Therefore 0.565656...=56/99
DC
Answered by Daanyaal C. • Maths tutor
4624 Views

Solve the equation ((2x+3)/(x-4))-((2x-8)/(2x+1))=1

Step 1: Multiply everything by x-4 to give (2x+3) - ((2x-8)(x-4)/2x+1)=(x-4) Step2: Multiply everything by 2x+1 to give (2x+3)(2x+1)-(2x-8)(x-4)=(x-4)(2x+1) Step 3: Multiply out the brackets to give (4x 2 +8...
MT
Answered by Matthew T. • Maths tutor
9044 Views

How do you factorise a quadratic equation?

A quadratic expression is of the form ax ​2 +bx+c. It is often useful to know what values of x will make the expression equal to 0; these are known as the roots of the equation. An easy way of seeing what th...
TW
Answered by Tim W. • Maths tutor
5092 Views

How is trigonometry used on non-right angled triangles?

To do this, there are two rules, the Sine Rule and The Cosine Rule. The sine rule is a/Sin A = b/Sin B = c/Sin C. (the lower and uppercase are very important. The rule also stands if you write the entire thi...
BC
Answered by Bobbie C. • Maths tutor
119088 Views