1 way The method of opposite coefficients
We multiply equally so that one of the variables was expressed opposite numbers . I chose y
y = -x + 5 [ (-2)
5x + 2y = 14
-2y - 2x = - 10
2y + 5x= 14
------------------------- add the equation
3x = 4 ⇔ x = 4/3
We substitute the value of x to the equation. We can choose any
y = -x + 5 = - 4/3 + 5 = 15/3 - 4/3 = 11/3
Answer B
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2 way
method of substitution
y = -x + 5 y value we put into the second equation
5x + 2y = 14
y = -x +5
5x +2(-x + 5) = 14
y = -x + 5
5x - 2x + 10 = 14
y = -x + 5
3x = 14 - 10
y = -x + 5
3x = 4 [:3
y = -x + 5
x = 4/3 we can put an x value of the first equation
y = -x + 5 = - 4/3 + 5 = 15/3 - 4/3 = 11/3
Answer B
