Answer:
Step-by-step explanation:--0.9
4/9(2n)+4/9(-3)
(4x2/9)n+(4 x -3)/9
(8/9)n -12/9
8/9n-4/3
Answer:
Area = 370 m²
Cost to paint = £105
Step-by-step explanation:
Area of the wall of a cinema hall = Area of a trapezoid (1)+ Area of a rectangle (2) + Area of a trapezoid (3)
Area of a trapezoid =
where and are the parallel sides and h is the distance between these sides.
Area of trapezoid (1) =
= 69 m²
Area of the rectangle (2) = Length × Width
= 12 × 15
= 180 m²
Area of the trapezoid (3) =
= 121 m²
Now area of the wall = 69 + 180 + 121
= 370 m²
One tin covers the area = 25 m²
Number of tins required to paint the wall =
=
= 14.8
Therefore, number of tins to be purchased = 15
Cost to paint the complete wall = 15 × £7
= £105
Answer:
4. dy/dx = -2
8. dy/dx = 1/2 x^(-3/2)
10/ dy/dr = 4 pi r^2
Step-by-step explanation:
4. y = -2x+7
dy/dx = -2(1)
dy/dx = -2
8. y = 4 - x^-1/2
dy/dx = - (-1/2x^ (-1/2-1)
dy/dx = 1/2 x^(-3/2)
10. y = 4/3 pi r^3
dy/dr = 4/3 pi (3r^2)
dy/dr = 4 pi r^2