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How do you expand (2x+9)^2?

(2x+9) 2 = (2x+9)(2x+9) Use FOIL to expand these brackets: First - ( 2x +9)( 2x +9) --> 4x 2 Outside - ( 2x +9)(2x+ 9 ) --> 4x 2 + 18x Inside - (2x +9 )( 2x +9) --> 4x 2 + 18x + 18x Last - (2x +9 )(...
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Answered by Alec M. • Maths tutor
9147 Views

5x - 2 > 3x + 11

Firstly we need to get all the x's on one side and the numbers on the other side. So if we add 2 to both sides we get 5x > 3x + 13. Now as we want the x's on the right hand side, we need to subtract both ...
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Answered by Sam C. • Maths tutor
4243 Views

How do I solve two simultaneous equations?

Supposing we have two equations x+2y=5 and 3x-y=10 and we want to find x and y we can use the following techinque. Multiply both the RHS and the LHS of the second equation by 2, giving us 6x-2y=20. Then add ...
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Answered by Theano X. • Maths tutor
4407 Views

What is the derivative?

The derivative is a measure of the rate of change of f(x) as x varies. Alternatively it is the gradient of the tangent at a specific point of the graph. There are different rules for finding the derivative d...
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Answered by Theano X. • Maths tutor
3856 Views

How to find the derivative of sqrt(x) from first principles?

Graphical explanation leading to the expression that we need to develop (Lim(a->0) (sqrt(x+a) - sqrt(a))/(a). Then we need to understand how to rearrange a fraction involving square roots (multiplication ...
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Answered by Olivier D. • Maths tutor
2247 Views