IF you are solving for d:
isolate the D, do the opposite of PEMDAS.
-d/6 + 12 = -7
(subtract 12 from both sides)
-d/6 + 12 (-12) = -7 (-12)
-d/6 = -19
(multiply 6 to both sides)
-d/6(6) = -19(6)
-d = -19(6)
-d = -144
-d/-1 = -144/-1
d = 144
hope this helps
Probability=13/52*12/51*11/50*10/49=11/4165
7 yrds/sec because in the course of two seconds, he runs 14 yrds divide that by 2 to get 7 yrds/sec. you can allo chech with the next time which is 3 seconds more and he goes 21 yards more.