Algebra-1

To solve the given system of equations using the elimination method, we can subtract the second equation from the first equation to eliminate the variable "y". Let's perform the subtraction:

(3x + y) - (x + y) = -21 - (-5)

Simplifying the equation, we have:

3x - x + y - y = -21 + 5

The y terms cancel out (y - y = 0), and the x terms combine:

2x = -16

To solve for x, we divide both sides of the equation by 2:

2x / 2 = -16 / 2

x = -8
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