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Write x^2+6x-7 in the form (x+a)^2+b where a and b are integers

Complete the square.We want a quadratic we can simplify.Halve the linear term coefficient (6) and square it.Add it to the (x²+6x) term and subtract it from the 7.x²+6x+(6/2)²

Answered by George B. • Maths tutor

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Write as a single fraction in it's simplest form: 2/(y+3)-1/(y-6)

The aim is to find a common denominator, we first therefore cross multiply to get:(2(y-6)-(y+3))/((y+3)(y-6))After expanding the relevant brackets we are left with:(2y-12-y-3)/((y+3)(y-6))Which is simply:...

Answered by James F. • Maths tutor

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Solve the simultaneous equations to find x and y: 2x - 2y = 20, x + 4y = 5

Equation1: 2x - 2y = 20, equation 2: x + 4y = 5First method (subtraction):Multiply equation1 by 2: 4x - 4y = 40Add the two equations together canceling out the y unknowns: 4x + x = 40 + 5Solve for ...

Answered by John S. • Maths tutor

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How do I calculate a percentage increase? For example; there are 15 fish in a fish tank, after a year they have bred and now there are 20 fish in the tank. By what % has the number of fish increased?

Original value = 15 New Value = 20 Difference = New value - original value 20 - 15 = 5
(Difference / original) x 100(5/15) x 100 = 33.3%

Answered by Seyi A. • Maths tutor

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Circle with centre C, and points A,B,D and E on the circumference of the circle. BD is the diameter of the circle. Angle CDA is 18 deg and angle AED is 31 deg. Find angle EDA.

Circle theorem: angle in a semi-circle is a right angle.Therefore angle BAE = 90 + 31 = 121 degrees ABDE is a cyclic quadrilateral and:Circle theorem: Opposite angles in a cyclic quadrilateral sum to 180 ...

Answered by Jasmin H. • Maths tutor

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