A. If she completed 1/4, 3/4 are still left to be done over 5 days.
To find out how much per day, divide 3/4 by 5 (multiply the first number by the reciprocal of the second).
3/4*1/5= 3/20.
Final answer: 3/20
b. If she irons 3/20 a day, she should iron 6/20 or 3/10 over the course of two days, Thursday and Friday. 3/10 of 40 is 40*0.3= 12
Final answer: 12 shirts
we know that
step 1
multiply
by 
so

step 2
Divide numerator and denominator by 

therefore
the answer is

This is the concept of algebra, given that the area of a rectangular pool is (15x-9), the possible dimensions of the pool by factoring will be:
Area=length×width
Area=(15x-9)
factoring the above we get:
Area=3(5x-3)
therefore the possible dimension will be:
length=5x units
width=3 units
I believe 1 is 3.8, b/c 1.9*2 is 3.8, and the difference between exponents makes 3 zeros, so 2000.
The second one is 40, I confirmed this by doing .0001 to replicate 10 to the negative 4th power
By doing 9.5*.0001*40, I got the 0.038 from 1