Answer:
The solution is (-5, -2).
Step-by-step explanation:
We'll use "elimination by addition and subtraction."
Multiply the second row by -2. Our system
– 7x – 10y = 45
-3x - 5y = 25
becomes:
– 7x – 10y = 45
+6x + 10 y = -50
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-x = 5, so that x = -5.
Substituting -5 for x in the second equation results in
-3(-5) - 5y = 25, or 15 - 5y = 25. This reduces to
-5y = 10, so that y must be -2.
The solution is (-5, -2).
