multiply by 8 on both sides
(20)8 - 8(4b/8) = (18)8
160 - 4b = 144
subtract 160 on both sides
160 - 160 - 4b = 144 - 160
-4b = -16
divide by -4 on both sides
-4b/-4 = -16/-4
b = 4
(0,5) is your answer
Hope this helped and is correct
By working backwards,
<span>you get 76 as your answer because you have to remove the rightmost digit, right? so the three-digit number is </span>
<span>76x </span>
<span>(x stands for the rightmost digit, because we don't know what the rightmost digit is) </span>
<span>we are told we have to add six to the three digit number to get 76x, so we have to subtract 6 from 76x: </span>
<span>76x - 6 = ??? </span>
<span>since we assume that the original two-digit number is NOT 76, and any number from 760 to 765 inclusive minus 6 is logically in the 750-range, we can conclude that the original two-digit number is 75. </span>