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:
c
Step-by-step explanation:
Equation = 12 - -24 = ?
After keep, change, flip: 12 + 24 = ?
Answer = 36
Working out the expression 7(3ˣ) is first to calculate the value of 3ˣ then multiply the answer to 7.
For example, let x = 2
Then 7(3ˣ) = 7(3²) = 7 × 9 = 63
With the same value of x = 2, calculating 21ˣ = 21² = 441, which isn't the same answer with the expression 7(3ˣ)
I had this question. the correct answer was B for it.