First problem:
Start with
[tex]47\leq x+21[/tex]
Subtract 21 from both sides:
[tex]47-21 \leq x \iff x \geq 26[/tex]
So, we want all numbers greater than or equal to 26. You have to highlight the number line from 26 onwards.
Second problem:
Kendra already has $7.35. If the adds $2.87, she has 7.35+2.87. She need at least this amount, so we want either this amount, or something more. So, we have
[tex]x \geq 7.35+2.87[/tex]
which you can rework as
[tex]x-7.35 \geq 2.87[/tex]
by subtracting 7.35 from both sides, so that you can match one of the options
