The amount of money jeff earns varies directly with the number of hours he works. jeff worked 40 hours and earned $560. what is the constant of variation for jeff's earnings? a) 14 b) 40 c) 510 d) 560

Will mark the brainliest.paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each?