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#1 2016-04-24 07:46:43

1928389123
Guest

5 Problems - 2 Shape - 2 Algebra

I need help with the following problems:

Problem 1:

The area of a parallelogram is 15cm^2 correct to the nearest integer.
The shortest side of the parallelogram is 4.5cm correct to 2 significant figures.
The longest side of the parallelogram is 7.1cm correct to 2 significant figures.
Find the largest possible size of the two acute angles in the parallelogram.
Give your answer correct to 3.d.p.

Problem 2:

Using algebra, show that part of the line 3x+4y=0 is a diameter of the circle with equation x^2+y^2=25.

Problem 3:

Shape A is a regular polygon.

The ratio of the size of the interior angle to the size of the exterior angle is 7:2.
The ratio of the side length to the number of sides is 5:3.
Find the perimeter of shape A.

Problem 4:

Sue is making a toy rocket in her science lesson which is to be launched from the ground.

The flight path of the toy rocket can be modelled by the equation h=-2t^2+6t+1
h is the height in metres the rocket reaches above the ground
t is the time in seconds after the rocket is launched

Find the maximum height above the ground that the rocket reaches and the time it takes to reach this height.

Problem 5:

There are N boys in a class at school.
For every 2 boys in the class there are 3 girls in the class.
3 students are chosen at random and taken out of the class.
Given that the probability of choosing 3 boys is 1/30, show that 23N^2-114N+88=0


I've got some idea of what the answers are, but I'm not entirely sure if they are correct.

Explanations would be nice,

thanks!

#2 2016-04-24 10:06:14

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: 5 Problems - 2 Shape - 2 Algebra

Hi;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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