Answer:
3rd graph
Step-by-step explanation:
3m ≥ 21 whenever you see '≤ or ≥' then you know the circle must be filled
divide each side by 3 to isolate 'm':
m ≥ 7 This inequality, when graphed, should have a closed circle on the number 7 and the shading would be to the right because the symbol is indicates all values "greater than" 7
