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Simplify (2x+3)^2 - (2x +3)(x-5). Give your answer in the form ax^2 +bx +c

Break this down into two parts.
a. Multiply out the 1st bracket, (2x+3)^2: This goes to (2x+3)(2x+3) which is equal to 4x^2 + 9 +6x+6x . Collect the like terms to get 4x^2 +12x +9.
b. Multiply...

Answered by Kenji S. • Maths tutor

7802 Views

Why does this past tense verb take être instead of avoir like the others?

There are two groups of verbs in French which use être in the passé composé rather than avoir. The first group are the reflexive verbs (think of the morning routine verbs se laver, se lever, se doucher) a...

Answered by Genevieve S. • French tutor

1551 Views

Sketch a curve of f(x)= sin(x)/x

Start by analysing the parts of the function, it's clearly a combination of two functions: f = g(x) / h(x) and drawing them both out.Examine behaviour for -inf. and +inf.Notice a problem in a situation wh...

Answered by Maciej P. • Oxbridge Preparation tutor

1578 Views

Sodium hydroxide reacts with phosphoric(V) acid according to the equation: 3NaOH + H3PO4 -> Na3PO4 + 3H2O 25.00 cm3 of 0.10 mol dm-3 sodium hydroxide reacts with 0.05 mol dm-3 H3PO4. The volume of H3PO4, in cm3, required for neutralisation is?

This is a simple moles equation and the method with any moles equation is find the number of moles of something, use the chemical equation to work out the number of moles of the thing you need to find and...

Answered by Matthew E. • Chemistry tutor

13429 Views

A square based pyramid with corners ABCD has side length 6 cm. The distance from the centre of the square (C) to the top vertex of the pyramid (V) is 4 cm. Work out the total surface area of the pyramid.

The first thing I would do with this question is to draw it out to help visualise the shape.From this drawing you can see that the shape has 4 triangle shaped faces (let's call this triangle T1) and 1 squ...

Answered by Matthew E. • Maths tutor

4459 Views