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Expand and simplify (2x+4)(x+2)

In order to expand this expression, we use what is known as the FOIL method. This stands for First, Outside, Inside and Last. First, we multiply the first term in each bracket by each other. 2x multiplied...

Answered by Erin D. • Maths tutor

6694 Views

Express 6x^2+4x-1 in the form a(x+b)^2+c

In this case we need to complete the square as follows:6((x+2)^2-4)-1= 6(x+2)^2-24-1= 6(x+2)^2-25where a = 6, b = 2, c = -25

Answered by Ahmad H. • Maths tutor

3287 Views

A bag contains 4 red counters and some blue counters in the ratio 1:4 respectively. How many counters are there in the bag altogether?

Calculate how many blue counters there are first. 4 divided by 1 = 4.4 multiplied by 4 = 16.16 blue counters in the bag.4 red counters and 16 blue counters makes 20 counters in the bag.

Answered by EMMA B. • Maths tutor

3160 Views

Given that y = 16x + x^-1, find the two values of x for which dy/dx = 0

Expected layout of answer in an exam:y = 16x + x^-1dy/dx = 16 - x^-2dy/dx = 0 implies that 16 - x^-2 = 0this implies that 16 = x^-216 = 1/x²

Answered by Sawdah H. • Maths tutor

3625 Views

multiply out (2x-4)(x-2) and simplify.

The method I would use here is FOIL (first outer inner last). A common mistake is not multiplying out all terms, using FOIL will ensure you do this.The working I would expect to see:2x^2-4x-4x+8 (order sh...

Answered by Ben W. • Maths tutor

3603 Views