SOLUTION: I need help with my homework question for College algebra: a) Write a system of equations to represent the situation b) Put the system of equations into matrix form. c) Use Ga

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Question 746151: I need help with my homework question for College algebra:
a) Write a system of equations to represent the situation
b) Put the system of equations into matrix form.
c) Use Gaussian Elimination and backwards substitution to find the measure of each angle of the triangle.

The Question:
In triangle ABC, the measure of angle B is 32 degrees more than three times the measure of angle A. The measure of angle C is 58 degrees more than the measure of angle A. The sum of all three angles are 180 degrees.

Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Naming the internal angles as a, b, c for the points A, B, and C,
Three equations: b=32%2B3a, c=58%2Ba, a%2Bb%2Bc=180.

Putting into a matrix: rearrange each equation to be in the same type of format as the "180" equation.
System:
a%2Bb%2Bc=180
a-c=-58
3a-b=-32

Do something more to make the system. You will need the coefficients of the variables to form the matrix.

System:
a%2Bb%2Bc=180
a%2B0%2Ab-c=-58
3a-b%2B0%2Ac=-32

This is not yet arranged for rendering on algebra.com site, but your matrix to begin will be like this:
1___ 1___ 1___ 180
1___ 0___ -1___ -58
3___ -1___ 0___ -32

Can you continue from that?
(I had here a suggestion but am deleting it )
---Okay I see what to try.
Use R1 to eliminate the column 1 elements into zero in R2 and R3. Replace R2 with R2-R1. Replace R3 with R3-3*R1. Can you decide what to do next? -----