The equation (1) is divided by 2 to create new equivalent system of equations.
Step-by-step explanation:
The given systems of equations are:

Considering 8y instead of 8 in eq(1)
We need to identify what action was completed to create this new equivalent system of equations? 
Comparing given equations we came to know that equation(1) is divided by 2 to get the new equation i.e

While second equation is same as given.
So, The equation (1) is divided by 2 to create new equivalent system of equations.
Keywords:System of Equation
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-2.77x - 11.4. Is the answer to your question
Answer:
(4, 5 )
Step-by-step explanation:
x + y = 9 → (1)
x - y = - 1 → (2)
adding the 2 equations term by term will eliminate y
2x + 0 = 8
2x = 8 ( divide both sides by 2 )
x = 4
substitute x = 4 into either of the 2 equations and solve for y
substituting into (1)
4 + y = 9 ( subtract 4 from both sides )
y = 5
solution is (4, 5 )