How Do You Add Exponents?

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An exponent is a shorthand way of showing how many times to multiply a number by itself. The number 9 with a small raised 3 on its upper right, also commonly expressed as 9^3, represents the base of 9 to the 3rd power, for instance; the raised 3 is the exponent. Simplify multiplication of two exponents with the same base number using exponent addition.

  1. Recognize the common base number

    In some math expressions, the base numbers are given. In the formula 9^3 times 9^5, for instance, the base number is 9 in each case. In algebraic expressions, the formula might show x^3 times x^5.

  2. Add exponent numbers and combine the bases

    To multiply two like base numbers, add the exponents and merge them into one. In 9^3 times 9^5, adding the exponents 3 and 5 equals 8. Therefore, this two-part formula is simplified to 9^8.

  3. Solve the equation

    Use the simplified base number and exponent to solve the equation. If the objective was to solve for x when you multiply 9^3 times 9^5, 9^8 = x. Multiply 9 by itself, then multiply the result by 9 six more times, or use a scientific calculator and enter 9, the "x to the y power" key and 8.