Answer is 4 so C for you. I just did this with my brother! Hope this helped.
T=an+b
subtract an from each side
b=t-an
Step-by-step explanation:
Sheldon's brother shoveled 2/3 of the driveway
Remaining portion = 1 - ⅔
= (3-2)/3
= 1/3
Sheldon shoveled 3/4 of what was left= ¾ × ⅓
= ¼
Sheldon shoveled ¼ or 0.25 of the driveway
Ahmed shoveled ⁴/5 of half of the driveway = 4/5 × ½
= 2/5
Ahmed shoveled 2/5 or 0.4 of the driveway
0.4 > 0.25
therefore, Ahmed will have the larger area to shovel
13 2/3
Hope this helped :)
Correct! lines that have undefined slopes are always parallel to the y-axis as the change in x is 0. A gradient is calculated by the change in y divided by the change in x and anything divided by 0 is referred to as undefined.

(calculation for a gradient)
Hope that helps sorry if its a bit confusing :)