Bump
Anyone know the answers to these?
Solve the given sytem of equations
9x+12y+2z=23
21x+2y-5z=-25
-18x+6y-4z=-11
Solve the given system of equations by use of determinants
26L-52M-52N=39
45L+96M+40N=-80
55L+62M-11N=-48
Solve the given system of equation by determinants
6541x+4397y=-7732
3309x-8755y=7622
Solve the given system of equations by either by either substitution or elimination
0.66x+0.66y=-0.77
0.33x+1.32y=1.43
Since you have to do a number of these by determinants I'll do this one that way. Specifically, I'm using Cramer's rule.
First we need the determinant of the coefficient matrix. This is 2610.
Now to solve the system. By Cramer's rule we take the vector on the RHS and replace the columns of the coefficient matrix one by one:
-Dan
Simple? No. Without a calculator? Yes. But it's the exact same method and it will take you a while. I'd use Cramer's rule for this as that has less computation than most other methods I know. (Gaussian elimination would be a good alternate as it is easy to check your work.) I would think of this as an excellent way to exercise your algebra skills, but if you are being graded on it, use the calculator!
-Dan