Question

3

The perimeter of a triangle is (8y2 – 9y + 4). Find its third side, if two of its
sides are (3y2 – 5y) and (4y2 + 12) respectively.​

Answer 1

The length of the third side:

= y² - 4y - 8

Step-by-step explanation:

(8y²-9y+4) - ((3y² - 5y)+(4y² + 12))

= (8y²-9y+4) - (3y² + 4y² - 5y + 12)

= (8y²-9y+4) - (7y² - 5y + 12)

= (8y²-9y+4) - 7y² + 5y - 12

= 8y²- 7y² - 9y + 5y + 4 - 12)

= y² - 4y - 8