We are required to know if the point (4,10) is a solution of the equation
5x + 10y = 120
If a point is a solution of the given equation, then when we replace x = 4 and y = 10 in the equation, the condition must stand, that is:
5(4) + 10(10) should be equal to 120
Evaluating the operations, we have:
20 + 100 = 120
Note the result of the operations equals the right side of the equation, thus we conclude the point (4,10) is a solution of 5x + 10y = 120