This year, Benny is 12 years old. His brother Lenny’s age is 175% of Benny’s age. How old is Lenny?
1 answer:
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Answer:
x=-1/85; y=-283/85; z=2/17
Step-by-step explanation:
Using an algebraic method like elimination or substitution would take a lot of steps which could lead to mistake the calculations. In this case, I decided to use the Gaussian elimination. We can express the system in matrix form as follows:
To begin the calculations, we write the system in augmented matrix form and use the Gaussian elimination:
By applying the Gaussian elimination, the final matrix is the following:
In order to verify the results, it´s enough to substitute the calculated values in the original equations to see if the equalities are correct. Here you can see the verification for all of the equations:
