Given the function f(x) = the quantity of 3x minus 4, divided by 5 , which of the below expressions is correct?
a. f−1(x) = the quantity of 5x plus 4, divided by 3.
b. f−1(x) = the quantity of 5x minus 4, divided by 3.
c. f−1(x) = the quantity of negative 3x minus 4, divided by 5.
d. f−1(x) = the quantity of 4 minus 3x, divided by 5.

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle