Answer:
It takes her 25.2 mintes
Step-by-step explanation:
You can just multiply 21 by 1.2 because that's how long she takes per lap and you can get 25.2
Area of rectangular prism is given by:
A=2(wl+hl+lw)
where w=width h=height, l=length
checking for given options
1. 8 ft, by 4ft by 3ft
Area = 136 square feet
5. 3 feet by 5 feet by 7 feet
Area =142 square feet
so our first and last option matches the requirement of area less than 160 square feet.
Answer:
4xy + 4x² + 4xz
Step-by-step explanation:
4x(y+x+z)
4xy + 4x² + 4xz
<span>Let r(x,y) = (x, y, 9 - x^2 - y^2)
So, dr/dx x dr/dy = (2x, 2y, 1)
So, integral(S) F * dS
= integral(x in [0,1], y in [0,1]) (xy, y(9 - x^2 - y^2), x(9 - x^2 - y^2)) * (2x, 2y, 1) dy dx
= integral(x in [0,1], y in [0,1]) (2x^2y + 18y^2 - 2x^2y^2 - 2y^4 + 9x - x^3 - xy^2) dy dx
= integral(x in [0,1]) (x^2 + 6 - 2x^2/3 - 2/5 + 9x - x^3 - x/3) dx
= integral(x in [0,1]) (28/5 + x^2/3 + 26x/3 - x^3) dx
= 28/5 + 40/9 - 1/4
= 1763/180 </span>