Start by distributing the 7 to both terms on the left hand side, and the 5 to both terms on the right hand side.
7(x - 2) = 5(x + 4)
7x - 14 = 5x + 20
Now, to solve for x, start by isolating the variable as much as you can.
7x - 5x = 20 + 14
2x = 34
x = 17
