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The longest side in a right-angled triangle is 12cm. One of the shorter sides is 4 cm. Calculate the perimeter of the triangle

12² = 4² + x² [This is pythagoras' theorem (a² = b² + c²) ]
144 =16 + x ²
128 = x²
11...

Answered by Rachel C. • Maths tutor

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Express: (x^2 + 5x - 14) / (2x^2 - 4x) as a fraction in it's simplest form.

Answer: (x+7)/(2x)

Answered by • Maths tutor

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Make d the subject of the formula: 3d + dxy = 4

d (3 + xy) = 4
d = 4/(3 + xy)

Answered by • Maths tutor

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A cylinder has radius 2cm and height 9cm. A cone has radius r cm and height h cm. The ratio r : h is 1 : 4. The volume of the cone is equal to the volume of the cylinder. Work out the value of r.

Firstly, we will find the volume of the cylinder using the formula V_cylinder =π r²h . Inputting the numbers given in the question gives V_cylinder = 36π.Given that V_cylinder = V_cone, and usi...

Answered by Alice C. • Maths tutor

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If y = 1/x^3, find an expression for dy/dx

Write down y = 1/x³ This can be rewritten as y = 1x^-3 or just y = x^-3as if the x is on the bottom of the fraction, it can be rewritten with a negative version of the powe...

Answered by Pete B. • Maths tutor

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