Given the equation system:
[tex]\begin{gathered} 1)2x+y=20 \\ 2)6x-5y=12 \end{gathered}[/tex]To solve the system and determine the value of x, first step is to write one of the equations in terms of y:
[tex]\begin{gathered} 2x+y=20 \\ y=20-2x \end{gathered}[/tex]Then replace this expression in the second equation
[tex]\begin{gathered} 6x-5y=12 \\ 6x-5(20-2x)=12 \end{gathered}[/tex]Now that you have an expression with only one unknown, x, you can calculate its value.
Solve the parenthesis using the distributive property of multiplication
[tex]\begin{gathered} 6x-5\cdot20-5\cdot(-2x)=12 \\ 6x-100+10x=12 \\ 6x+10x-100=12 \\ 16x=12+100 \\ 16x=112 \\ \frac{16x}{16}=\frac{112}{16} \\ x=7 \end{gathered}[/tex]