Question 51579
By definition, two complementary angles must add up to 90.  Therefore, we have {{{16z-9+4z+3=90}}}.  We combine like terms and get {{{20z-6=90}}}.  Add 6 to both sides to get {{{20z=96}}} and now divide both sides by 20 gives us {{{z=96/20}}}.  Now using substitution, in the first equation we get {{{16*96/20-9}}} which reduces to {{{67.8}}}.  This means the second angle must be 90-67.8, or 22.2, degrees.  We can verify by substituting {{{96/20}}} in the second equation:  {{{4*96/20+3}}} simplifies to {{{22.2}}}.