The classroom is 8 meters long, 6.5 meters wide and 2 meters wide. The area of doors and windows is 26 square meters. What is the painting area for painting the walls and roofs around

The classroom is 8 meters long, 6.5 meters wide and 2 meters wide. The area of doors and windows is 26 square meters. What is the painting area for painting the walls and roofs around

Area of surrounding walls and roofs = 8 * 3.2 * 2 + 6.5 * 3.2 * 2 + 8 * 6.5 = 51.2 + 41.6 + 52 = 144.8
Painting area = 144.8-26 = 118.8

Try to write out a quadratic trinomial about x such that the coefficient of the quadratic trinomial is 3, the constant is - 4 and the value of the polynomial is 4 when x = 1

3X^2+5X-8=0

There is a quadratic trinomial about X, its quadratic coefficient is 3, the coefficient of the first term and the constant term are - 1, try to write this polynomial______ ．

∵ for the quadratic trinomial of X, if the coefficient of the quadratic term is 3, if the coefficient of the quadratic term is 3x2, if the coefficient of the quadratic term and the constant term are - 1, then the quadratic term is - X and the constant term is - 1, then the quadratic trinomial is 3x2-x-1