How can i add fractions with different denominators

For the function, f(x) = -5x 2, find f(-4).

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

Which is a logical conclusion based on the given information? a. figure abcd is a rhombus by the definition of a rhombus. b. segment ac is congruent to segment dc by cpctc. c. angle acb is congruent to angle adc by the angle-side-angle theorem. d. triangle acd is congruent to triangle cab by the hypotenuse-leg theorem.