we have that
Each week runs x miles per day for 5 days
that means
each week runs 5x miles
speed=distance/time
time=distance/speed
For 3 days of the week he runs at speed of 8 miles per minute
so
we have
distance=3x miles
speed=8 miles per minute
substitute
time=3x/8
For 2 days he runs at 2 miles per minute
so
we have
speed=2 miles per minute
distance=2x miles
substitute
time=2x/2
the total time is equal to
(3/8)x+(2/2)x
(3/8)x+(8/8)x=(11/8)x
this is the time in each week
so the part a is For 4 weeks
therefore
the expression is equal to
4*(11/8)x=(11/2)x=5.5x
answer part a is 5.5x
Part b
equivalent expression
we have
(11/2)x
If you multiply both numerator and denominator by the same number, you obtain an equivalent expression
Example
multiply by 3/3
so
(3/3)*(11/2)x=(33/6)x
is an equivalent expression