Question

one fourth of the opposite of the difference of five and a number is less than twenty

Answer 1

'of' means multiply

1/4 of (1/4 times ) the opposite of (-) difference of 5 and a number (5-n) is lesss than 20 (<20)

1/4 times -(5-n)<20
multiply both sides by 1/4
-(5-n)<5
multiply both sides by -1 remember to flip sign
5-n>-5
add n
5>n-5
add 5
10>n
n<10


the number is any number less than 10