Question:
Linear Algebra Problems on Echelon Method
1) Use the echelon method to solve the system of two equations in two unknowns.
9x+8y=72
-6x-3y=-48
Solve the problem.
2) Linda invests $25,000 for one year. Part is invested at 5%, another part at 6%, and the rest at 8%. The total income from all 3 investments is $1600. The income from the 5% and 6% investments is the same as the income from the 8% investment. Find the amount invested at each rate.
Use the Gauss-Jordan method to solve the system of equations.
x-y+8z =107
x+2y =21
2x+y+8z =80