Simultaneous Equations

[Jeros]

Guys can you just confirm that i have got this right, i realise its a bit late to change it now its handed in but:

An alloy contains 8cm cubed of copper and 7cm cubed of tin and a mass of 121 grams.

The 2nd alloy contains 9cm cubed of copper and 11cm cubed of tin, and a mass of 158 grams

Form 2 simultaneous equations to find out the density of copper and tin in grams/cm cubed, using x for the density of copper and y for the denisty of grams

 

[Lamp]

You still at school then ? Homework ?

 

[Jeros]

You still at school then ? Homework ?

College, last question of my assingment

 

[kirennia]

It's been a while but that'd come up with

8c + 7t = 121g
9c + 11t = 158g

Erm...could just multiply the t's together or cs, or multiply the top one by 9/8 or 11/7...take them away from each other and it should sort it out.

72c+63t = 1089g
72c+88t = 1264g

take the top from the bottom.

25t = 175g

t = 7grams

Put that into any one of them for work out the weight of copper.

8c+49 = 121g
8c = 72g
c = 9g

Don't forget to annotate properly unlike I am. Been a long while since I've done this but I presume it's right.

 

[Jeros]

thats what i got

I love you and i want to put my love into you

 

[Solo]

thats what i got

I love you and i want to put my love into you

Simultaneous Ejectulations

 

[crispy]

Guys can you just confirm that i have got this right, i realise its a bit late to change it now its handed in but:

An alloy contains 8cm cubed of copper and 7cm cubed of tin and a mass of 121 grams.

The 2nd alloy contains 9cm cubed of copper and 11cm cubed of tin, and a mass of 158 grams

Form 2 simultaneous equations to find out the density of copper and tin in grams/cm cubed, using x for the density of copper and y for the denisty of grams

Impossible to calculate since the copper and tin atoms in the two alloys probably pack in different ways thus altering the density ^_^

 

[Bugz]

There's three ways to do simultaneous equations generally:

substitute one into the other
minus or plus directly
multiply/divide to get the same t or the same c in both some equations and then minus or plus.

Personally, I'm an avid fan of substitution but each to their own