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 owned everything in Egypt
If AB is parallel to CD which statement must be true?
what jobs did middle class members had in 1900? A.working in farms B.unemployed C.in europe fighting the war D.working in offices, stores, factories, and othe
Suppose y varies directly as x, and y = 8 when x = -2. Which of the following is the correct equation to set up to solve for the constant of variation? A) 8 = k
Which supercontinent forms the core of North America? A. Gondwana B. Pannotia C. Laurentia D. Rodinia​
Which Type of thermal energy uses electromagnetic waves to transfer energy
A and b have opposite directions, and they both have a magnitude of 7 what must be true about a and b
the product of 34 and the number of pounds
Plz answer my question quick I really need it!!!
which statement forms part of cell theory​