Question

What is negative four times a number plus nine is no more than the number minus twenty one ?

Answer 1

First, we've got to make this into an equation with numbers, not words. We'll use x as "the number" when we make the equation. By "no more than," I'm assuming you mean to use the "less than or equal to" sign.
-4x + 9 ≤ x - 21
Now that we have the equation, we just have to solve for x.
-4x + 9 ≤ x - 21
-4x ≤ x - 21 - 9
-4x ≤ x - 30
-4x - x ≤ -30
-5x ≤ -30
-x ≤ - 6
x ≥ 6
In the end, x is greater than or equal to 6, because we had to change the entire equation from negative to positive.

Answer 2

`-4x+9 <= x-21\-5x+9<=-21\-5x<=-30\x>=6`

<= means less than or equal to and >= means greater than or equal to.

So, the final answer is x >= 6.