Question

21 is greater than or equal to 3(a-7) +9

Answer 1

21≥3(a-7) +9
first, just solve it like a normal equation
Distribute
21≥3a-21+9
Combine numbers
21≥3a-12
Solve like equation
33≥3a
11≥a
"a" has to be less than or equal to 11 for the inequality to be true