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Show that (4x – 5)^2 – 5x(3x – 8) is positive for all values of x

(4x-5)^2-5x(3x-8) (16x^2-40x+25)-(15x^2-40x) 16x^2-15x^2-40x+40x+25 x^2+25 if x = positive, x^2 will be positive. if x = negative, x^2 will be positive. x^2 is positive for all values of X, +25 will not make...
JM
Answered by Joseph M. • Maths tutor
4287 Views

GCSE Chemistry- Describe the structure of an atom?

Atoms have a small nucleus surrounded by electrons. The Nucleus- It is in the middle of the atom It contains protons and electrons Protons are positively charged +1 Neutrons have no charge 0 Nucleus has a po...
UI
Answered by Umair I. • Chemistry tutor
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((2x + 3)/(x-4)) - ((2x-8)/(2x+1)) = 1

x=0.81
AS
Answered by Amelia S. • Maths tutor
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A 10kg cube of iron with length 5cm is resting on a table surface. Assuming the acceleration under gravity of the block is 9.81ms^(-2), what is the pressure on the table?

Pressure is given by P=F/A, where F is force and A is area. Neither are given in the question, but A is the area of the cube in contact with the table; this is the area of one face of the cube, so A=L L=0.05...
WH
Answered by William H. • Physics tutor
4478 Views

You are shown a diagram of a right angled triangle, with the hypotenuse labelled c and the other sides labelled a and b. If a is 7m long and c is 10m long, what is the length of b?

A simple implementation of Pythagoras' Theorem a 2 +b 2 =h 2 , and as in the question c is the hypotenuse, a 2 +b 2 =c 2 . (Side Note - in exams, the question may not specify which length is the hypotenuse -...
WH
Answered by William H. • Maths tutor
4592 Views