first since we have the variable "x" on both sides of the equation, we can subtract the lower number to make sure x is only on one side (subtract 10x from both sides)
20x + 4 = 10x + 100
10x + 4 =100
now we can subtract 4 from both sides
10x = 96
now we can divide both sides by 10 to isolate x
x = 9.6
hope this helped