Answer:
see explanation
Step-by-step explanation:
(1)
Given the perimeter then the third side is the perimeter subtract the sum of the 2 given sides, that is
third side
= 4x + 3y - (x - y + x + y)
= 4x + 3y - 2x ← collect like terms
= 2x + 3y
(2)
The area (A) of a triangle is calculated as
A = [tex]\frac{1}{2}[/tex] bh ( b is the base and h the height )
Here b = 2x + 6 and h = x - 2, thus
A = [tex]\frac{1}{2}[/tex](2x + 6)(x - 2) ← expand factors using FOIL
= [tex]\frac{1}{2}[/tex](2x² + 2x - 12) ← distribute
= x² + x - 6 ← in standard form
