Expressed in figures, this is equal to 8,100,000.
80+1= 81
81 = 8.1 x 101
Write the repeating digits over the same number of 9s and simplify: 0.81... has two repeating digits ⇒ the denominator has two 9s, ie 99. ⇒ 0.81... = 81/99 = 9/11
81,000,000,000,000
81 = 92 or 8.1 × 101
81 is a whole number whose simplest form is 81.
81+0=81
Just writing "81" is mathematical enough for my taste. After all, that's a number, and numbers are mathematical.
80+1= 81
Without exponentsWith exponentsIn word form
81 = 8.1 x 101
81/100
No, -81 is not an irrational number because it can be represented in the form x/y = -81
Write the repeating digits over the same number of 9s and simplify: 0.81... has two repeating digits ⇒ the denominator has two 9s, ie 99. ⇒ 0.81... = 81/99 = 9/11
81,000,000,000,000
81/10
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