I’m pretty sure it’s just 28
Let ab be a 2 digit number, then ab=10a+b, where a and b are digits, a≠0.
"the difference between the integer and the product of its two digits is 12"
10a+b - (a*b)=12
10a+b-ab=12
factorize b:
10a+b(1-a)=12
subtract 10 from both sides, to produce a factor (1-a) or (a-1) and then factorize:
10a-10+b(1-a)=2
10(a-1)+b(1-a)=2
(a-1)(10-b)=2
(a-1)(10-b) can be (1,2), (2, 1), (-1, -2), (-2, -1)
if a-1=1 and 10-b=2, then a=2, b=8
if a-1=2, and 10-b=1, then a=3, b=9
if a-1=-1, then a=0, which is not possible
if a-1=-2, then a=-1, which is not possible
so the solutions (a, b) are (2, 8) and (3, 9)
Then the integers are 28, 39
Answer: 28, 39
B. Decreases
(Hopefully I’m right!)
4.50+4.50=9.00=9
+
2.39+2.39=4.78
+
1.99
=
15.77
15.77-25=-9.23
Answer:2739
Step-by-step explanation:
