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

Who was the roman emperor who first legalized christianity and founded the first st. peter's in rome?
What event in europe in 1814 allowed the british to concentrate all their forces in america?
What is -3/4, 0.5, 2/3, -7/3, 1.2 in order from least to greatest
what are some observable properties that can be used to identify these metals?
When virginia and kentucky in the late 1700s and south carolina in the 1830s refused to follow federal law they were practicing a.federalism. b.nullification. c
Can someone please help me with number 31?
If every dimension of a two dimensional figure is multiplied by k, by what quantity is the area multiplied?
what is an example of an ecumene (ap human geography)?
Which health-related activity could be effectively completed using only Internet resources?
The word that means "the ridges on fingerprints" is_________ a. delta c. minute b. masthead d. whorl