Answer:
Step-by-step explanation:
Three forces are in equilibrium . 
Let us represent forces in vector form ie in the form of i and j .
F₁ is acting along positive x axis ( at a 0° angle )
F₁ = 12 i 
F₂ is acting along positive y axis ( at a 90° direction)
F₂ = 18 j
Suppose F₃ is represented by X i + Y j 
Total of three forces is zero .
F₁ + F₂ + F₃ = 0 
12 i + 18 j + F₃ = 0 
F₃ = - 12i - 18 j 
So x - component of F₃ = - 12 i 
X - component of F₃ is equal to 12 N in magnitude and is acting in negative x direction ie at 180° direction . 
similarly y - component is 18 N acting in negative y direction.