SOLUTION: Solving a system of equations word problems using matrices Your teacher is giving you a test worth 100 points containing 40 questions. There are two-point and four-point question

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Question 1159504: Solving a system of equations word problems using matrices
Your teacher is giving you a test worth 100 points containing 40 questions.
There are two-point and four-point questions on the test. How many of each
type of question are on the test?
Found 2 solutions by Boreal, greenestamps:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
x 2 points for 2x points
40-x 4 points for 4(40-x) points
2x+4(40-x)=100
2x+160-4x=100
-2x=-60
x=30 2 point questions for 60 points
40-x=10 4 point questions for 40 points

Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


Gauss-Jordan elimination?
Cramer's Rule?
or maybe something else?

Just specifying "using matrices" doesn't tell us what method of solution you want to use.