Page 236 - Excel for Scientists and Engineers: Numerical Methods

CHAPTER 9 SYSTEMS OF SIMULTANEOUS EQUATIONS 213

Problems

Answers to the following problems are found in the folder "Ch. 09 (Simultaneous
Equations)" in the "Problems & Solutions" folder on the CD.

1. Solve the following system of four simultaneous equations:
3x1 + l.lx2-2x3 - l.8x4= 11
3.2X1 + 2.1~2 + 32x3 + 2.2x4= 0
3.4X1 + 2.3X2 + 4.h3 + 32x4 = 6
1.6~1 + 1.1~2-3.2X3+2.4~4= -5

2. Current flow in a circuit is described by Kirchhoffs laws. A particular
circuit network yielded the following three simultaneous linear equations:
1, + 12 - 13 = 0
21, + 513 = 7
211 - 412 = 2
Find the currents Zl, Z2 and Z3 in the circuit network.

3. Solve the following system of four simultaneous equations:
2.829~1 - 2.253~2 + 6.777~3 + 3.970~4 = 6.235
1.212~1 + 1.995~2 + 2.265~3 + 8.008~4= 7.319
4.553~1 -t 5.681~2 + 8.850~3 + 1.302~4 = 5.730
5.808~1- 5.030~2 + 0.098~3 + 1.832~4 = 9.574