The expression for the number of diagonals that we can make from one vertex of a n sided polygon is:
- (a)2n + 1
- (b)n – 2
- (c)5n + 2
- (d)n – 3 A variable is a letter that is used to represent one or more numbers. The numbers are the values of the variable. A variable expression is a collection of numbers, variables and operations. Here are some examples. VARIABLE EXPRESSION MEANING OPERATION 8y =8 × y = 8 (y) 8 times y Multiplication = 16 ÷ b 16 divided by b Division 4+s 4 plus s Addition 9–x 9 minus x Subtraction The expression 8y is usually not written as 8 × y because of possible confusion of symbol ‘ × ’ with the variable x. Replacing each variable in an expression by a number is called evaluating the expression. The resulting number is the value of the expression. Write the variable Substitute values Simplify the numerical → → expression for variables expression 15-04-2018
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(d) n – 3 A variable is a letter that is used to represent one or more numbers. The numbers are the values of the variable. A variable expression is a collection of numbers, variables and operations. Here are some examples. VARIABLE EXPRESSION MEANING OPERATION 8y =8 × y = 8 (y) 8 times y Multiplication = 16 ÷ b 16 divided by b Division 4+s 4 plus s Addition 9–x 9 minus x Subtraction The expression 8y is usually not written as 8 × y because of possible confusion of symbol ‘ × ’ with the variable x. Replacing each variable in an expression by a number is called evaluating the expression. The resulting number is the value of the expression. Write the variable Substitute values Simplify the numerical → → expression for variables expression 15-04-2018