2) Let a.b.c be the three sides of the triangle ABC, the equation (B+C)x2+ radical number 2(a-c)x-3/4(a-c) =0 has equal real roots, a.b.c satisfies the condition of a-5b+2c=0, and the triangle ABC is isosceles. B: the value of c
3) The teacher asked the students to make an isosceles trapezoid kite with diagonal lines perpendicular to each other. Its area is 450 square centimeters, so the bamboo strips used in the two diagonal lines need at least ().
A 30 cm one.
B 60 cm
About 45 cm
D 90 cm
A chemical plant in our city has 290kg of raw materials A and 212kg of raw materials B. It is planned to produce 80 products A and B with these two raw materials. It takes 5kg of raw materials A and1.5kg of raw materials B to produce a product, and the production cost is 120 yuan. To produce a product B, 2.5 kilograms of raw materials and 3.5 kilograms of raw materials are needed, and the production cost is 200 yuan.
(1) Can the current raw materials of this chemical plant guarantee production? If possible, there are several production schemes, please design them;
(2) Let the total cost of producing A and B products be Y yuan, and the quantity of a product be X. Try to write the functional relationship between Y and X, and use the nature of the function to explain which production scheme has the lowest total cost (1). What is the minimum production cost?