Let N be a whole number.
The phrase "seven times a whole number" can be written as: 7N.
The phrase "twice the sum of the number and eight" can be written as 2(N+8).
This means that the phrase "seven times a whole number decreased by twice the sum of that number and eight" may be written as:

On the other hand, the phrase "four times the number increased by 20" translates to:

Since those two expressions are related through the expression "is equal to", then we can write an equation:

To solve this equation, use the distributive property to rewrite -2(N+8) as -2N-16:

Sum like terms on each side of the equation:

Add 16 to both sides of the equation:

Add 20+16:

Substract 4N from both sides of the equation:

Add the like terms 5N and -4N:

Substitute N=36 in the original equation to check this answer:
