Think of a number. add two. multiply by three. add your original number. multiply by 2. add 2. subtract your original number. divide by 7. add three. subtract your original number. add five. why is the answer always ten?

X is the number
adding 2 we get x+2
multiply by 3 we get 3x+6
add original number we get 4x+6
multiply by 2 we get 8x+12
add 2 we get 8x+14
minus original number we get 7x+14
divide by 7 we get x+2
add 3 we get x+5
minus original number we get 5
add 5 we get 10

because the numer you pick cancels out in the end

we can write it out fully into one big equation
if x is the number
then the resulting expression is looking like this