# Help With Linear Equations !!!!

• Feb 26th 2013, 09:01 AM
joshuafalls
Help With Linear Equations !!!!
Hi,

Ive got 3 questions about equations that are below, Im not very good with equations but im hoping one of you guys can show me how to work it out.

1. F = MV - MU divided by T / Find F when M = 2, U =4, V = 7, T =3

Given that y = x2 + 3x - 5, find y when x = 4

2. Bag of Kitty Litter : £2.20 per bag + £3 postage

Let N be the number of kitty bags that Jenny buys.
Write down an equation to represent the amount, £=A, that jenny will pay for N bags of cat litter by mail order

3. The area of a rectangle has the same numerical value as the perimeter of the square, By forming an equation in X, find the length of the rectangle.

..................
6cm
(x + 4) cm

2. ...............
18cm

I really hope one of you guys can help as im stumped.

Thanks
• Feb 26th 2013, 09:40 AM
HallsofIvy
Re: Help With Linear Equations !!!!
Quote:

Originally Posted by joshuafalls
Hi,

Ive got 3 questions about equations that are below, Im not very good with equations but im hoping one of you guys can show me how to work it out.

1. F = MV - MU divided by T / Find F when M = 2, U =4, V = 7, T =3

Is this $\displaystyle F= \frac{MV- MU}{T}$? Then $\displaystyle F= \frac{(2)(7)- (2)(4)}{3}$. That's just arithmetic.

Quote:

Given that y = x2 + 3x - 5, find y when x = 4
Is this $\displaystyle y= x^2+ 3x- 5$? (Use "^" to indicate powers.) Then $\displaystyle y (4)^2+ 3(4)- 5$.

Quote:

2. Bag of Kitty Litter : £2.20 per bag + £3 postage

Let N be the number of kitty bags that Jenny buys.
Write down an equation to represent the amount, £=A, that jenny will pay for N bags of cat litter by mail order
Multiply N times 2.20 and add 3.

Quote:

3. The area of a rectangle has the same numerical value as the perimeter of the square, By forming an equation in X, find the length of the rectangle.

..................
6cm
(x + 4) cm

2. ...............
18cm

I really hope one of you guys can help as im stumped.
I can't understand your picture. But the perimeter is the sum of the lengths of all sides and area is "width times height". Set those equal.

Thanks[/QUOTE]