Subtract the left side, simplify, divide by the x-coefficient, than add the opposite of the constant.
[tex]5x-3=7x+7+3x\quad\text{given}\\\\0=(7x+7+3x)-(5x-3)\quad\text{subtract the left side}\\\\0=x(7+3-5)+(7+3)\quad\text{collect terms}\\\\0=5x+10\quad\text{simplify}\\\\0=x+2\quad\text{divide by 5}\\\\-2=x\quad\text{add the opposite of the constant}[/tex]
The value of x is -2.