SOLUTION: I apologize for putting two questions here, but they're both set up the same with the elimination method, and I need help with both. ( I figured its not the same as posting all my

Algebra ->  Matrices-and-determiminant -> SOLUTION: I apologize for putting two questions here, but they're both set up the same with the elimination method, and I need help with both. ( I figured its not the same as posting all my       Log On


   



Question 433203: I apologize for putting two questions here, but they're both set up the same with the elimination method, and I need help with both. ( I figured its not the same as posting all my homework)
I need help to solve 9x + 2y = 2 by the elimination method,
21x + 6y = 4
and this problem the same way:
2x + 3y = 18
5x – y = 11

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) ++9x+%2B+2y+=+2+
(2) +21x+%2B+6y+=+4+
Multiply both sides of (1) by 3 and subtract
(2) from (1)
(1) ++27x+%2B+6y+=+6+
(2) +-21x+-+6y+=+-4+
+6x+=+2+
+x=+1%2F3+
and
(1) ++9%2A%281%2F3%29+%2B+2y+=+2+
3+%2B+2y+=+2+
+2y+=+-1+
+y+=+-1%2F2+
check answer:
(2) +21x+%2B+6y+=+4+
+21%2A%281%2F3%29+%2B+6%2A%28-1%2F2%29+=+4+
+7+-+3+=+4+
+4+=+4+
OK
----------------
(1) 2x+%2B+3y+=+18
(2) 5x+%96+y+=+11
Multiply both sides of (2) by 3,
The add the equations
(1) 2x+%2B+3y+=+18
(2) 15x+%96+3y+=+33
+17x+=+51+
+x+=+3+
and
(1) 2%2A3+%2B+3y+=+18
+6+%2B+3y+=+18+
+3y+=+12+
+y+=+4+
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