Solve the following system of equations:
x + 3y = 9
x − 2y = 14

Which sum or difference identity would you use to verify that cos (180° - ∅) = -cos ∅? a. sin (α -β) = sin α cos β – cos α sin β b. cos (α -β) = cos α cos β – sin α sin β c. cos (α -β) = cos α cos β + sin α sin β d. sin (α + β) = sin α cos β + cos α sin β

60 2(x + 2) in the diagram, gef and hef are congruent. what is the value of x?

Simplify using positive exponents only.