Top answers

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
4170 Views

((2x + 3)/(x-4)) - ((2x-8)/(2x+1)) = 1

x=0.81
AS
Answered by Amelia S. • Maths tutor
3382 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
4473 Views

Solve the simultaneous equations: 2x - y = 4 and x + 2y = 7

Solve: 2x - y = 4 and x + 2y = 7 There are two methods to solve this, you can either calculate one of the variables from either equations and then substitute to the second one or try to multiply one of the e...
EK
Answered by Eliza K. • Maths tutor
16625 Views

Work out the value of 2a^2 + b^3 when a = 5 and b = –3

It is best to approach this question in parts, then combine the parts to find your solution. This question may be split into parts, as follows: Firstly, if a = 5, then a 2 = 5 2 = 5 x 5 = 25. So a 2 = 25 Sec...
TD
Answered by Tutor51449 D. • Maths tutor
14865 Views