Mod 4 Vocab--8th Grade

Mod 4 Vocab--8th Grade

Vocab Quiz will be Thursday, October 7th

Equation​

​Says that two things are equal

​Like Terms

​Terms whose variables (such as x or y) with any exponents (such as the 2 in x²) are the same.

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Examples:7x and 2x are like terms because they are both "x".

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3x² and −2x² are like terms because they are both "x²".

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But 7x and 7x² are NOT like terms (the exponents are different), they are unlike terms.

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Like terms can be added together.

Coefficient

​A number used to multiply a variable (4x means 4 times x, so 4 is a coefficient)

​Variable

​A symbol for a value we don't know yet. It is usually a letter like x or y.

Example: in x + 2 = 6, x is the variable.

Why "variable" when it may have just one value? In the case of x + 2 = 6 we can solve it to find that x = 4. But in something like y = x + 2 (a linear equation) x can have many values. In general it is much easier to always call it a variable even though in some cases it is a single value.

​Linear Equation

​linear equation is an equation for a straight line

​Slope

​Proportional Relationships

When quantities have the same relative size. In other words they have the same ratio.

​Systems of Equations

​A System of Linear Equations is when we have two or more linear equations working together.

​Y-intercept

​The point where a line or curve crosses the y-axis of a graph.

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In other words: find the y value when x equals 0

​Slope-Intercept Form

​The slope intercept form of a straight line is one of the most common forms used to represent the equation of a line. The slope intercept formula can be used to find the equation of a line when given the slope of the straight line and the y-intercept(the y-coordinate of the point where the line intersects the y-axis).

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