Answer:
Step-by-step explanation:
Circumference of the column 
Circumference of a circle
Therefore:
Area of a Circle 
Since radius of the cross section of the column =9 meters
Area of the cross section of the column
The rationals being closed under subtraction means that if we start with two rational numbers and subtract them, we get another rational number. Choice c subtracts two rational numbers but gets the wrong answer, so isn't support for anything. Choice b is rational too because the square root of 4 is 2.
Answer: b
(88 + 92 + 96 + x) / 4 = 90
(276 + x) / 4 = 90
276 + x = 90 * 4
276 + x = 360
x = 360 - 276
x = 84 <=== he would need an 84
2x-8y////2r+5+3r-s+11=5r+16-s////-7x+7
Algebra is made up of quantities and the operations performed on them are addition, subtraction, multiplication and division.
<span>Algebra is a branch of mathematics. It concerns itself with operations on sets of numbers or other elements. The sets of numbers and elements are represented by symbols. Algebra can be seen as a generalisation of arithmetic. Letters are substituted for numbers in Algebra. For example, x + 2x will always equal 3x no matter what values the symbol x represents. The algebraic can also include polynomial functions of one or more of the variables. </span>
