E is the answer I am pretty sure.
Answer:
median
Step by step:
the line segment from a vertex to the midpoint of the opposite side. It is also an angle bisector when the vertex is an angle in an equilateral triangle or the non-congruent angle of an isoceles triangle.
J=john
m=mary
j is 2 times as old as mary
j=2 times m
sum is 21
m+j=21
find mary
subsitute
j=2m therefor subsitute 2m for j
m+2m=21
add like terms
3m=21
divide by 3
m=7
mary=7
*HOPE I HELPED!*
Hope you can see my workout in the picture I attached below.
f⁻¹(x) =
AND
f⁻¹(19) =
