All angles in a triangle add up to 180 so 180 - 60 = 120 then 180 - 155 = 25 then 25+65 = 90 that is the remaining angle but finally 180 - 90 = 90 is the missing angle
<em>multiply both sides by 5 </em> 3(15k+10)=5(12k-9)
<em>get rid of the brackets</em> 45k+30=60k-45
<em>take away 45k to both sides</em> 30=15k-45
<em>plus 45 to both sides</em> 75=15k
<em>divide both by 15</em> k=5
10 (1/2) = 5
hope this helps
