Answer:
x = 4 , y = 5
Explanation:
the sides of an equilateral are congruent , then
AB = BC = 11
set up a system of equations and solve simultaneously, that is
- x + 3y = 11 → (1)
4x - y = 11 → (2)
multiplying (2) by 3 and adding to (1) will eliminate y
12x - 3y = 33 → (3)
add (1) and (3) term by term to eliminate y
11x + 0 = 44
11x = 44 ( divide both sides by 11 )
x = 4
substitute x = 4 into either of the 2 equations and solve for y
substituting into (1)
- 4 + 3y = 11 ( add 4 to both sides )
3y = 15 ( divide both sides by 3 )
y = 5
solution is x = 4 and y = 5