Question

Consider the system of equations 5x + y = 9 and 4x - y =18 what is the value of the x-coordinate of the solution

Answer 1

`\left \{ {{5x+y=9} \atop {4x-y=18}} \right.\\\\=>\left \{ {{5x+4x=9+18} \atop {y=4x-18}} \right.\\\\<=>\left \{ {{9x=27} \atop {y=4x-18}} \right.\\\\<=>\left \{ {{x=3} \atop {y=4x-18}} \right.`

=> the value of the x-coordinate is 3

Explanation: