Question

The product of two 2- Digit numbers is 1998. If the product of their units digit is 28 and that of tens digit is 15, find the numbers. Answer with out imaginary letter or number.​

Answer 1

Step-by-step explanation:

let the two digits number be x and y where,

x=10a+b

y=10c+d

xy =1998

ac=16

bd=28

xy =(10a+b)(10c+d)

1998=(10a+b)(10c+d)

1998=100ac+10ad+10bc+bd

1998=100x15+10ad+10bc+2

1998-1528=10(ad+bc)

470=10(ad+bc)

47=ad+bc

47=15d/c+bc

47=15d+bc2/c

47c=15d+bc2

bc2=47c+15d=0

c=-q+-√Q2-4pr/2p

=-(-47)+-√(47)2-4xbx15xd/2b

=47+-√2209-60xbd /2b

=47+-√2209-60x28/2b

=47+-√2209-1608/2b

=47+-√529/2b=47+-23/2b

c=70/2b,24/2b

c=35/b,12/b

bc=35 or 12

by substituting

47=ad+35

ad=12

a*28/b=12

47=ad+12

ad=35

a/b=35/28