9x+12x-21=27
How do I solve ?

Find parametric equations for the line tangent to the curve of intersection of the surfaces at the given point. surfaces: xsquared2plus+2yplus+2zequals=1212 yequals=33 point: left parenthesis 1 comma 3 comma five halves right parenthesis

What are the constants in this expression? -10.6+9/10+2/5m-2.4n+3m

Suppose i flip two identical coins. what is the probability that i get one head and one tail?