Final answer:
The expression 9x²-45x can be rewritten by factoring out the greatest common factor which is 9x, resulting in 9x(x - 5).
Step-by-step explanation:
To rewrite the expression 9x²-45x by taking out the greatest common factor and putting it in front, we need to first identify that common factor. The greatest common factor (GCF) of 9x² and 45x is 9x because 9x can divide both terms evenly. Rewriting the expression, we take out the GCF and factor it as follows:
9x² - 45x = 9x(x - 5).
Here, we have factored out 9x from both terms, which leaves us with the factor (x - 5) when we divide each term by 9x.