add them together then divide by 5
81 +86 +81 +76 +71 = 395
395/5 = 79
your average was 79
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
Hey the answer is 2713 cm
Answer:
Step-by-step explanation:
you just need to add both equations
you will get 3y=12+6=18
3y=18
y=6
now replace y=6
3x+12=6
3x=6-12
3x=-6
x=-2
(-2,6)