Charles Beaudry sells computer hardware for a computer firm. He is paid 4 percent commission on the first $8,000 of sales, 6 percent on the next $10,000 of sales, and 8 percent on sales over $18,000. What is his commission of $21,278 in sales?

It’s 5 points actually

You move the constant to the right side and change its sign to be 9z= -6 -8. that’s the first step.the second step would be calculate the difference of -8-6 to get -14. you equation should now be 9z=-14the last step is to divide both sides by 9 to get z=-14/9hope this