Which triangle is a 30°-60°-90° triangle?

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 4 p plus 4 x plus 2 pxequals56. suppose also that p and x are both functions of time, measured in days. find the rate at which x is changing when xequals2, pequals6, and startfraction dp over dt endfraction equals1.5.