Answer:
side 3 = 4x² - 8x + 9
Step-by-step explanation:
a crow has feathers, so it is a bird"
perimeter = 7x² - 5x + 3
side₁ = 3x² + 2x - 1
side₂ = x-2
to find the perimeter of a shape, you add the lengths of all the sides.
the formula looks something like this:
perimeter = side₁ + side₂ + side₃
we know side₁ and side₂ but not side₃
to find side₃, we just need to subtract side₁ and side₂ from the perimeter:
side₃ = perimeter - (side₁ + side₂)
now, plug in what we know via PEMDAS
7x² - 5x + 3 - (3x² + 2x - 1 + x - 2) = s₃
7x² - 5x + 3 - (3x² + 3x - 3) = s₃ distribute the negative to the ()
7x² - 5x + 3 - 3x² - 3x + 3 = s₃ combine like terms
4x² - 8x + 9 = s₃
