Find the surface Area of the Triangular Pyramid

Find the roots of the equation below. x^2 - 6 + 9 = 0

Icould really use some with this question.

Helll ! 1,400 tons of wheat of two different varieties was delivered to the silo. when processing one variety, there was 2% of waste and 3% during the processing of the second variety of wheat. after the processing, the amount of remaining wheat was 1,364 tons. how many tons of each variety of wheat was delivered to the silo?