Question

The perimeter of a triangle is 8y² - 9y+ 4 and its two sides are 3y² - 5y and 4y² + 12.
Find its third side.​

Answer 1

Answer:

$let \: third \: side \: is \: x \\ 3y {}^{2} + 4y {}^{2} - 5y + 12 + x = 8y {}^{2} -9y + 4 \\ 7y {}^{2} - 5y + 12 + x = 8y { }^{2} - 9y + 4 \\ x = 8y {}^{2} - 7y {}^{2} - 9y + 5y + 4 - 12 \\ x = 2y {}^{2} - 4y - 12$