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Solve the equation: x^2 - 9x + 20 = 0

This is a quadratic equation, and is likely that x can satisfy either of two values. We know these must multiply to form 20 and summate to -9, and thus they are (x-4) and (x-5). Hence, x is either 4 or 5....

Answered by Pippa M. • Maths tutor

7663 Views

Expand and Simplify: 16=(x-3)(x+3)

16 = (x-3)(x+3) --> 16 = x^2+3x-3x-9 --> 16 = x^2-9 --> x^2=25 --> x = +5 or -5

Answered by Thaarabi T. • Maths tutor

4174 Views

Prove algebraically that (4n + 1)² − (2n − 1) is an even number for all positive integer values of n.

First of all expand the brackets and simplify the expression given:(4n+1)(4n+1)-(2n-1)= 8n²+8n+1-2n+1= 8n²+6n+2= 2(4n²+3n+1). Since the expression can be factorised with 2...

Answered by Shiv M. • Maths tutor

10652 Views

If a particle of mass m is launched vertically upwards from the ground with velocity u m/s, how long will it take to return to the ground in terms of m, u and g?

Taking upwards to be positive, and using the 'suvat' equation s=ut+1/2at² we know that u=u, a=-g and s=0 when the particle returns to the ground. Then we solve for t:
0=ut-1/2gt²

Answered by Jackie V. • Maths tutor

3287 Views

How to recognise and make the link between probability and the algebraic demands of this question?

While I doubt students will ask this exact question, think it provides the basis for what are usually the most difficult questions in GCSE papers, and students would usually be unsure where to start. My i...

Answered by Neeraj K. • Maths tutor

2975 Views