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

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![\large\begin{array}{l} \textsf{b) }\mathsf{(g\circ f)(-2)}\\\\ =\mathsf{g\big[f(-2)\big]}\\\\ =\mathsf{\sqrt{f(-2)}}\\\\ =\mathsf{\sqrt{(-2)^2-6\cdot (-2)+2}}\\\\ =\mathsf{\sqrt{4+12+2}}\\\\ =\mathsf{\sqrt{18}}\\\\ =\mathsf{\sqrt{3^2\cdot 2}}\\\\ =\mathsf{3\sqrt{2}}\\\\\\ \therefore~~\boxed{\begin{array}{c}\mathsf{(g\circ f)(-2)=3\sqrt{2}} \end{array}}\qquad\checkmark \end{array}](https://tex.z-dn.net/?f=%5Clarge%5Cbegin%7Barray%7D%7Bl%7D%20%5Ctextsf%7Bb%29%20%7D%5Cmathsf%7B%28g%5Ccirc%20f%29%28-2%29%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7Bg%5Cbig%5Bf%28-2%29%5Cbig%5D%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7B%5Csqrt%7Bf%28-2%29%7D%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7B%5Csqrt%7B%28-2%29%5E2-6%5Ccdot%20%28-2%29%2B2%7D%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7B%5Csqrt%7B4%2B12%2B2%7D%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7B%5Csqrt%7B18%7D%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7B%5Csqrt%7B3%5E2%5Ccdot%202%7D%7D%5C%5C%5C%5C%20%3D%5Cmathsf%7B3%5Csqrt%7B2%7D%7D%5C%5C%5C%5C%5C%5C%20%5Ctherefore~~%5Cboxed%7B%5Cbegin%7Barray%7D%7Bc%7D%5Cmathsf%7B%28g%5Ccirc%20f%29%28-2%29%3D3%5Csqrt%7B2%7D%7D%20%5Cend%7Barray%7D%7D%5Cqquad%5Ccheckmark%20%5Cend%7Barray%7D)
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Tags: <em>composite function composition evaluate algebra</em>
Answer:
-S = 15
Step-by-step explanation:
You are asked to find the opposite of the given value.
<h3>Opposite</h3>
The opposite of an integer value is obtained by changing its sign.
S = -15
-S = -(-15) = 15
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<em>Additional comment</em>
Equivalently, you are multiplying by -1. The product of an even number of minus signs is a plus sign. We usually don't write the plus sign for a numerical value.