To solve this equation, we need to find the values of x that make the expression (* - 5) (7x - 21) equal to zero.
According to the zero product property, if the product of two factors is equal to zero, then at least one of the factors must be zero.
So, we can set each factor equal to zero and solve for x:
(*) - 5 = 0 or 7x - 21 = 0
Solving for (*) in the first equation, we get:
(*) = 5
Solving for x in the second equation, we get:
7x = 21
x = 3
Therefore, the two values of x that are solutions to the equation are x = 3 and (*) = 5.