To check if the equation "1 + 4(3x - 10) = 12x - 39" is true, we can substitute a value for x and see if both sides of the equation are equal.
One way to solve this equation is to first simplify the expression on the left side of the equation:
1 + 4(3x - 10) = 1 + 4(3x) - 4(10) = 1 + 12x - 40
Now we have:
1 + 12x - 40 = 12x - 39
Subtracting 12x from both sides:
-11x + 41 = - 39
Subtracting 41 from both sides:
-11x = -80
Finally, dividing both sides by -11:
x = 7.27
So, x = 7.27 is a solution of the equation and the equation is true.