Show that a, b,c, d are in proportion if 2a^2+3b^2:2c^2+3d^2::2a^2-3b^2:2c^2 -3d^2​

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

Proportions in triangles solve for x

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !