Respuesta :
Answer:
2. 325 minutes.
Step by step explanation:
We will substitute our given number of minutes in our both equation one by one to find the correct option.
1. Let us substitute m= 775 in both equations.
[tex]CA=22+0.13m[/tex]
[tex]CA=22+0.13\cdot 775[/tex]
[tex]CA=22+100.75=122.75[/tex]
[tex]CB=44+0.09(m-100)[/tex]
[tex]CB=44+0.09(775-100)[/tex]
[tex]CB=44+0.09\cdot675[/tex]
[tex]CB=44+60.75=104.75[/tex]
[tex]104.75\neq122.75[/tex]
We can see that both plans have different costs , therefore, 1st option is incorrect.
2. Let us substitute m= 325 in both equations.
[tex]CA=22+0.13m[/tex]
[tex]CA=22+0.13\cdot 325[/tex]
[tex]CA=22+42.25=64.25[/tex]
[tex]CB=44+0.09(m-100)[/tex]
[tex]CB=44+0.09(325-100)[/tex]
[tex]CB=44+0.09\cdot 225[/tex]
[tex]CB=44+20.25=64.25[/tex]
[tex]64.25=64.25[/tex]
When Vanessa has used the phone for 325 minutes, the cost for Plan A and the cost for Plan B will both be $64.25.Therefore, 2nd option is correct choice.
3. Let us substitute m= 32.5 in both equations.
[tex]CA=22+0.13m[/tex]
[tex]CA=22+0.13\cdot 32.5[/tex]
[tex]CA=22+4.225=26.225[/tex]
[tex]CB=44+0.09(m-100)[/tex]
[tex]CB=44+0.09(32.5-100)[/tex]
[tex]CB=44+0.09\cdot -67.5[/tex]
[tex]CB=44-6.075=37.925[/tex]
[tex]37.925\neq26.225[/tex]
4. Let us substitute m= 764 in both equations.
[tex]CA=22+0.13m[/tex]
[tex]CA=22+0.13\cdot 764[/tex]
[tex]CA=22+99.32=121.32[/tex]
[tex]CB=44+0.09(m-100)[/tex]
[tex]CB=44+0.09(764-100)[/tex]
[tex]CB=44+0.09\cdot 664[/tex]
[tex]CB=44+59.76=103.76[/tex]
[tex]121.32\neq103.76[/tex]
Therefore, 4th option is incorrect.
