Let's let x be the number of t-shirts.
So the first company charges $43 plus $9 per shirt. For x shirts, the cost is the base fee plus 9 times x, or [tex]C=9x+43[/tex].
The second company charges a $58 fee plus $8 per shift. The cost is [tex]C=8x+58[/tex].
Now, we want to find which fee is less when we are buying 20 shirts. We plug in 20 for x.
The first company charges [tex]C=9(20)+43=223[/tex].
The second company charges [tex]C=8(20)+58=218[/tex].
The costs are VERY close, but the second company ultimately charges less.