The answer is 12+3r because 4 times 3=12 then the 3r which you cannot add because they are no others variables that are r
Answer:
relationship between base and perpendicular is given by tan angle
tan ?=perpendicular./base
tan?=5/16
?=tan-¹(5/16)=17.35=17
-x-y=1
-y=1+x
y=-1-x
-1-x=-2x+9
-x=-2x+10
x=10
y=-1-10
y=-11