Only genius’s pleasee

Of four points are collinear, they are also coplanar

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

Lena draws a square with an area that is greater than the area of rectangle b. what are two possible side lengths of lena's square? explain.