Substitution usually refers to the method of elimination in math, mainly used to solve systems of two linear equations, and the core idea is to turn a "two-variable" problem into a "one-variable" one to solve it.
math
"Greater than or equal to" is a mathematical operator, commonly used to compare two numbers. It's a combination of the 'greater than' symbol (>) and the 'equal to' symbol (=), meaning the number on the left is greater than or equal to the number on the right.
The 'greater than' symbol in math is >, which means the number on the left is bigger than the one on the right. For example, 5 > 3 is read as '5 is greater than 3'.
Division is a basic operation in math. Simply put, it's the process of finding one number when you know the product of two numbers and one of the numbers. It's usually written as dividend ÷ divisor = quotient. You can think of it as the 'reverse' of multiplication. For example, if you know 3×4=12, then 12÷4 equals 3.
Sampling is picking out a part from a big group of research subjects to represent the whole, then analyzing that part to figure out the overall situation.
The equator is the circle on the Earth's surface with a latitude of 0°, dividing the Earth into the Southern and Northern Hemispheres, and it's also the longest line of latitude on Earth.
Compass-and-straightedge construction refers to the method of drawing geometric figures using only an unmarked straightedge and a compass, performing a limited number of steps. For example, drawing a line segment equal to a given one is one of its basic applications. This way of constructing shapes originated in ancient Greece and is a classic topic in plane geometry, emphasizing logical rigor and the limitations of the tools.
The multiplication table usually refers to the 9x9 multiplication table, which goes from 'one times one equals one' to 'nine times nine equals eighty-one.' It's a basic tool for doing math calculations. It uses the rules of the decimal system to simplify complex multiplication into easy-to-remember rhymes.
Multiplication is a shortcut for adding the same number repeatedly. The result is called the product, and the symbol is '×'.
A hypersurface is an n-1 dimensional submanifold in n-dimensional space. Simply put, it's a geometric structure whose dimension is one less than the surrounding space. It's the generalization of lines in a plane and planes in space to higher-dimensional spaces.