Answer:
Simple sum. The symbol Σ (sigma) is generally used to denote a sum of multiple terms. This symbol is generally accompanied by an index that varies to encompass all terms that must be considered in the sum.
Answer:

Step-by-step explanation:
To work out the volume of this shape you will first need to work out the area of the triangle. To work out the area of the triangle you would multiply the base of 12 by the height of 4.1, which gives you 49.2. You would then need to divide 49.2 by 2, which gives you 24.6. This is because the formula for the area of a triangle is the same as that of a square, however a triangle is half of a square with the same length and width. To work out the volume you would multiply the area of the triangle, which is 24.6 by the height of 9, which gives you 221.4
1) Multiply 12 by 4.1.

2) Divide 49.2 by 2.

3) Multiply 24.6 by 9.

138 x ? = 75
? = 75/138 = 0.544(3sf)
so about 54.35% (2dp) decrease
Answer:
18 gallons
Step-by-step explanation:
We'll find out how much of the total container was lost when pouring out by subtracting 2/3 from 1/2.
2/3 = 4/6
1/2 = 3/6
4/6 - 3/6 = 1/6
1/6 of the total amount the container could hold was lost when 3 gallons was poured out. This means that 1/6 of the container equals to 3 gallons. We can then simply multiply 3 by 6 to find the number of gallons of liquid the container can hold.
3 * 6 = 18 gallons
Checking my answer:
18 * 2/3 = 6 * 2 = 12
12 - 3 = 9
1/2 of 18 = 9
This means that our answer is correct.
The answer is
round cake - 82.42 in²
rectangular cake - 114 in²
Round cake:
d = 7 in
r = d/2 = 7 in / 2 = 3.5 in
h = 2 in
The surface are of a cylinder is:
A = 2πr² + 2πrh
The surface are of the round cake (which is actually a cylindrical cake) excluding the bottom is:
A = 2πr² + 2πrh - πr²
A = πr² + 2πrh
A = 3.14 * 3.5² + 2 * 3.14 * 3.5 * 2
= 38.46 + 43.96
= 82.42 in²
Rectangular cake:
w = 6 in
l = 9 in
h = 2 in
The surface are of a rectangle is:
A = 2wl + 2wh + 2lh
The surface are of the rectangular cake excluding the bottom is:
A = 2wl + 2wh + 2lh - wl
A = wl + 2wh + 2lh
A = 6 * 9 + 2 * 6 * 2 + 2 * 9 * 2
= 54 + 24 + 36
= 114 in²
Step-by-step explanation: This answer is not mine but JcAlmighty’s so all credits go to them.