Top answers

If the area of a sector of a circle is 3*pi cm^2 and the circle has a radius of 6cm, what is the angle of the sector?

The total area of the circle is pi*r^2 = 36 piThis means that the sector is 1/12th of a circle.A circle has 360 degrees and so the angle of the sector wil be 360/12 = 30 degrees.
CA
Answered by Cameron A. • Maths tutor
3672 Views

Solve the simultaneous equations: 4x+5y=13 and 3x-2y=27

Equation 1 is 4x+5y=13 - multiply it by 3, Equation 2 is 3x-2y=27 - multiply it by 4, New equation 1 is 12x+15y=39, New equation 2 is 12x-8y=108, Subtract new equation 2 from new equation 1 - 23y=-69 therefo...
TD
Answered by Thea D. • Maths tutor
4815 Views

Solve the simultaneous equations: (1) x^2 + y^2 = 25 and (2) y - 3x = 13

Sub (2) y = 13 + 3x into (1)x^2 + (13 + 3x)^2 = 25x^2 + 169 + 39x + 39x + 9x^2 = 2510x^2 + 78x + 144 = 05x^2 + 39x + 72 = 0 (/2)5 72 = 360 - need a b=360 such that a+b=39a = 24 b = 155x^2 + 24x + 15x + 72 = ...
MM
Answered by Meghna M. • Maths tutor
3326 Views

Square ABCD has length (x+3)cm and area 10cm^2. Show x^2 + 6x = 1

First sketch square ABCD. Split length into 3cm and then xcm for side AB and the same for side AD. Split the area of this square into 4 segments (a, b, c and d) such that a is a 3cm by 3cm square, b and c ar...
MM
Answered by Meghna M. • Maths tutor
4993 Views

Henry invest £8000 in youtube at a compound interest rate of 2% per year. He wants to earn more than £500 interest. Work out the least time, in whole years, that this would take?

Each year his money will increase by 2%, meaning he will get 102% of his money from the previous year. This can be written as 1.02. After n years, he will make 8000 x 1.02 n . Calculate this for 1, 2, 3, 4.....
GL
Answered by Gillian L. • Maths tutor
4300 Views