Question on Graphs and Relations on past exams?

[hotdog169]

im about to do a SAC on linear and its going to made up of previous exams, ive been doing heaps of Short answers and i havent stumbled across blending (where there is 3 varaibles , x , y and another one). Does anyone recall doing a exam that has it on it?

[hotdog169]

urgent!! does anyone know?

[_avO]

you'll only see 3 variables if there are three different linear equations intersecting at 3 different points (like a triangle) which i havnt seen in graphs & relations, they generally deal with just two linear equations. but even if you do get one its not very difficult its like doing simultaneous equations three times instead of once

eg.

2 = 2x + 3y + 0.5z
1 = 4x + 2y - z
4 = 0.5x + 2y + z

you'd separate them into two different simultaneous equations (use one of the equations in both)
2 = 2x + 3y + 0.5z               and        1 = 4x + 2y - z
1 = 4x + 2y - z                                   4 = 0.5x + 2y + z

then you'll get an equation from each but instead it would only have two variables
3 = 4y + 2z                         and         31 = 14y + 9z

then like you would any other question solve for z or y blah blah blah
3 = 4y + 2z
31 = 14y + 9z