1.The sum of the digits of a two digit number is 12. If the digits are reversed , the new number is 4/7 times the original number.Determine the original number.
2006-10-12 03:59:55 · 4 answers · asked by anam p 1 in Science & Mathematics ➔ Mathematics
I will write the equations for you and you will solve them
The first number is ab. The second is ba.
So a+b=12
10b + a = 4/7 *(10a + b)
find a and b now.
2006-10-12 04:04:37 · answer #1 · answered by Dr. J. 6 · 0⤊ 0⤋
No. Linear equations in 2 variables.
a + b = 12
10a + b -(7/4)(10b + a) = 0
and go from there âº
Doug
2006-10-12 11:06:36 · answer #2 · answered by doug_donaghue 7 · 0⤊ 0⤋
84
2006-10-12 11:05:37 · answer #3 · answered by Fredrick Carley 2 · 0⤊ 0⤋
a + b = 12
a = 12 - b
10a + b = (4/7) * (10b + a)
10*(12-b) + b = (4/7) * (10b + 12 - b)
120 - 10b + b = (4/7) * (9b + 12)
120 - 9b = (36b + 48) / 7
840 - 63b = 36b + 48
99b = 792
b = 8
a = 4
84 (qed)
2006-10-12 11:06:07 · answer #4 · answered by Dave 6 · 0⤊ 0⤋