B.40
Because 32/8=4. So you have to multiply 10x4 to get 40 girls
What exactly where you asked to do?
make x subject of formula?
Answer:
The length is 
The width is 
Step-by-step explanation:
we know that
The area of rectangle is equal to

we have

so
-----> equation A
------> equation B
substitute equation B in equation A and solve for L


using a graphing tool------> solve the quadratic equation
The solution is 
see the attached figure
<em>Find the value of W</em>