Area = length X width
A = L(12 ft) x W(9 ft) but since the cost of carpet is given in square yards not square feet we need to convert
A = (12 ft)(1 yd/3 ft) x (9 ft)(1 yd/3 ft) 1 yard = 3 feet so 1 foot = 1/3 yard
A = 4 yd x 3 yd divide by 3 ft which cancels the original ft and leaves yd's
A = 12 square yards
Cost = Area x price per yard
Cost = 12 sq yd X $35.00/ sq yd multiply and the sq yd's cancel leaving just cost in dollars
Cost = $420.00
Let them be X and Y..
now...
yx=100 ....
y=100/y ...
now...
x+y= s....where s is their sum...
but y=100/x
now....x+100/x=s..
by differentiating both sides with respect to x..
1-100/x^2=ds/dx
but ds/dx=0..
100=x^2 ..
x=10..
so y=10
He could make 6 squares, because each square has 4 sides. And 24 divided by 4 is 6. The number fact that i used is 24 divided by 4