Tyrone2pon Tyrone2pon
  • 02-03-2017
  • Mathematics
contestada

The sum of the digits of a certain two-digit number is 7. Reversing its digits increases the number by 9.

Respuesta :

cartermike359
cartermike359 cartermike359
  • 02-03-2017
a + b = 7
10a + b + 9 = 10b + a

9a - 9b = -9
9a = 9b - 9
a = b - 1

Plugging back into the original equation:

(b - 1) + b = 7
2b - 1 = 7
2b = 8
b = 4
a = 3

34

Answer Link

Otras preguntas

David made 30 cups of tea per hour. Andrew made 35 cups of coffee per hour. This week David made an additional 10 cups of tea. Write an expression that represen
The range of the function f(k) = k2 + 2k + 1 is {25, 64}. What is the function’s domain?
The Sino-Japanese War exposed military weakness in A. China. B. Japan. C. Korea. D. Russia.
What is the term for words such as after, before, following, and then in the chronological writing process? A. signal words B. indefinite pronouns C. conjunct
6. All of the following changes occurred in China between 1500 and 1800 except (1point) A. An increase in population B. Growth in manufacturing and trade C. Imp
Compare and contrast a series and parallel circuit. Give at least one way that they are alike and one way that they are different
what is the equivalent to 7.4 kilograms
Do I capitalize zebra in this sentence? Meet Timmy the zebra.
Which concerns of the Anti-Federalists were satisfactorily resolved in the Constitution?
what are the factors of (r+t)(e)