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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

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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

3460 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

3893 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

3918 Views

Solve the simultaneous equations: 3x+2y=11, 2x-5y=1.

Step 1) Label Equations 1) 3x+2y=11 2) 2x-5y=1 Step 2) Multiply so that one variable has same coefficient in both equations.1)x5 15x+10y=55 ...

Answered by Harry B. • Maths tutor

5084 Views