Cross multiply:
8 * 10 = 50 * 4
Simplifying
8 * 10 = 50 * 4
Multiply 8 * 10
80 = 50 * 4
Multiply 50 * 4
80 = 200
Solving
80 = 200
Couldn't find a variable to solve for.
This equation is invalid, the left and right sides are not equal, therefore there is no solution