Determine which of the expressions are equivalent. :: (3+9i) + (-9+i)
:: (1 + 2i) – (7 + 8i)
:: 14-(4-3i) - 9i
:: -8- (-2+i) +11i
:: 3i(4 + 2i)
:: (2+2i)(1+4i)

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ab=4 and bc=3, find ah, ch and bh.

Which of the fallowing best completes the sequence 5,10,15, a) 30 b) 22 c)25 d)35

Which is a true statement comparing the graphs of x^2/6^2-y^2/8^2 = 1 and x^2/8^2-y^2/6^2 the foci of both graphs are the same points. the lengths of both transverse axes are the same. the directrices of = 1 are horizontal while the directrices of = 1 are vertical. the vertices of = 1 are on the y-axis while the vertices of = 1 are on the x-axis.