Ihave this geometry problem that i just can't process right now. we're working on similar triangles using proportions. i need on prob 24.

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Fractions can be added and subtracted only if they're fractions. a. like b. proper c. improper d. unlike

Suppose babies born after a gestation period of 32 to 35 weeks have a mean weight of 25002500 grams and a standard deviation of 800800 grams while babies born after a gestation period of 40 weeks have a mean weight of 27002700 grams and a standard deviation of 385385 grams. if a 3232-week gestation period baby weighs 21252125 grams and a 4040-week gestation period baby weighs 23252325 grams, find the corresponding z-scores. which baby weighs lessless relative to the gestation period?