10 + what equals -6.2

PLEASE HELP ME ASAP;))

Which is f(5) for the function –2x2 + 2x - 3?

Atorch and a battery cost 2.50 altogether. the torch costs 1.50 more than the battery. what fraction of the total price is the torch? give your answer in its simplest form.

In δabc, m∠acb = 90°, cd ⊥ ab and m∠acd = 45°. find: a find cd, if bc = 3 in