SOLUTION: The sum of three numbers is 6. Thrice the third number when added to first number gives 7. On adding the sum of second and third number to three times the first number we get 12. F

Algebra ->  Equations -> SOLUTION: The sum of three numbers is 6. Thrice the third number when added to first number gives 7. On adding the sum of second and third number to three times the first number we get 12. F      Log On


   

Question 1019542: The sum of three numbers is 6. Thrice the third number when added to first number gives 7. On adding the sum of second and third number to three times the first number we get 12. Find the three numbers using determinants (Cramer’s rule).
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
x%2By%2Bz=7
x%2B3z=7
3x%2By%2Bz=12
So then,
A=%28matrix%283%2C3%2C%0D%0A1%2C1%2C1%2C%0D%0A1%2C0%2C3%2C%0D%0A3%2C1%2C1%29%29
abs%28A%29=6
.
.
A%5Bx%5D=%28matrix%283%2C3%2C%0D%0A7%2C1%2C1%2C%0D%0A7%2C0%2C3%2C%0D%0A12%2C1%2C1%29%29
abs%28A%5Bx%5D%29=15
.
.
A%5By%5D=%28matrix%283%2C3%2C%0D%0A1%2C7%2C1%2C%0D%0A1%2C7%2C3%2C%0D%0A3%2C12%2C1%29%29
abs%28A%5By%5D%29=18
.
.
A%5Bz%5D=%28matrix%283%2C3%2C%0D%0A1%2C1%2C7%2C%0D%0A1%2C0%2C7%2C%0D%0A3%2C1%2C12%29%29
abs%28A%5Bz%5D%29=9
.
.
x=abs%28A%5Bx%5D%29%2Fabs%28A%29=15%2F6=5%2F2
y=abs%28A%5By%5D%29%2Fabs%28A%29=18%2F6=3
z=abs%28A%5Bz%5D%29%2Fabs%28A%29=9%2F6=3%2F2