Respuesta :

Answer:

B

Step-by-step explanation:

x-5+3x-5+90=180 you set it up this way because you need to find what x is equal to and by adding those two equations plus 90 then setting the against 180 you can find x because all three angles in a triagnle add up to 180.

x-5+3x-5+90=180

4x-10+90=180              you combined like numbers

4x+80=180                   combined like numbers

    -80    -80                 subtract 80 from both sides because you are trying to---                                     get x alone

4x=100                          now to get x alone you have to divide 4 from both     ----                                     sides

/4    /4

x=25                              answer