Mathematical problems of first degree function in the second grade of junior high school 1. A worker works from 7:00 to 11:00 in the morning. At first, he takes 15 minutes to prepare, and then processes a part every 15 minutes ① Find the functional relationship between Y in the morning time and X parts processed ② How many parts did he finish machining at 8 o'clock?

Mathematical problems of first degree function in the second grade of junior high school 1. A worker works from 7:00 to 11:00 in the morning. At first, he takes 15 minutes to prepare, and then processes a part every 15 minutes ① Find the functional relationship between Y in the morning time and X parts processed ② How many parts did he finish machining at 8 o'clock?

Let y and X be y = KX + B
X=7.25 Y=0 X=7.5 Y=1
∴0=7.25k+b 1=7.5k+b
∴k=4 b=-29
∴Y=4X-29
When x = 8, y = 3
He processes three parts at 8 o'clock