The work of a student to solve a set of equations is shown:

equation a: y = 4 − 2z
equation b: 4y = 2 − 4z

step 1: −4(y) = −4(4 − 2z) [equation a is multiplied by −4.]
4y = 2 − 4z [equation b]
step 2: −4y = 4 − 2z [equation a in step 1 is simplified.]
4y = 2 − 4z [equation b]
step 3: 0 = 6 − 6z [equations in step 2 are added.]
step 4: 6z = 6
step 5: z = 1

in which step did the student first make an error?
step 1
step 3
step 4
step 2

What number should be added to both sides of the equation to complete this square? x^2-10x=7

As part of an annual fundraiser to raise money for diabetes research, diane joined a bikeathon. the track she biked on was 1,920 yards long. diane biked 38.5 laps. her sponsors agreed to donate an amount of money for each mile she biked. how many miles did she bike? first fill in the blanks on the left side using the ratios shown. then write your answer. given ratios: 5280ft / 1 mi , 1 mi /5280 ft , 1,920 yards / 1 lap , 1 lap / 1,920 yards , 3 ft / 1 yard , 1 yard / 3 ft. blanks: 38.5 laps / 1 yard x (blank) x (blank) x (blank) = (blank) miles i'm really confused on how to do this, and the explanations aren't exactly . if you could walk me through how to do this, it would be greatly appreciated.

15 points! write the slope-intercept form of the equation of the line through the given point with the given slope. use y-y = m(x-x) to solve. through (2,5) slope= undefined