Question

Is (1,2) the solution to the following system of equations? Show your work that proves whether it is or is not the solution.

Answer 1

Answer: No (1,2) is not the solution but (4,-1) is the solution.

Explanation:

solve by elimination

-4 (x - 3y)= 7(-4) multiply this equation by -4 to eliminate the x term

4x + 2y =4

New equation -4x + 12y=-28

4x + 2y =-1 4

14y= -14

divide both sides by 14

y= -1

Plot the y solution into one of the equation to find x

4x + 2(-1)=14

4x -2 = 14

+2 +2

4x=16

x=4

Answer 2

no

Explanation:

To determine if the given point is a solution.

Substitute the values x = 1, y = 2 into the left side of both equations and if equal to the right side then it is a solution.

Must be true for both equations

x - 3y = 1 - 3(2) = 1 - 6 = - 5 ≠ 7

4x + 2y = 4(1) + 2(2) = 4 + 4 = 8 ≠ 14

Thus (1, 2) is not a solution to the system of equations.