I need help on these 2 questions how did I get it wrong? and for question 3 I'm not supposed to have the = sign so what am I supposed to replace it with?

Answer:
3.
m + 7 ≥ 20
Subtract 7 on both sides,
m ≥ 20 - 7
m ≥ 13
The answer is m ≥ 13.
( you need to include both > and =, that is ≥ )
4.
2.1x = 23.1
Divide 2.1 on both sides,
x = 23.1 / 2.1
x = 11
Answer:
For problem #3, we are given [tex]m+7\geq 20[/tex] so we would just subtract 7 from both sides to get rid of the 7 on the left and that would end up subtracting 7 from 20 also leaving us with [tex]m\geq 13[/tex].
For problem #4, we are given [tex]2.1x=23.1[/tex] so we would just divide both sides by 2.1 which would get rid of the 2.1 on the left and that would also make us divide 23.1 by 2.1 leaving us with [tex]x=11[/tex].
Hope this helps! Let me know if you have any questions