Two 10 by 10 grids are shown. the first grid has 4 columns and 6 squares shaded green. on the same grid, 6 squares and 4 columns are shaded red. on the same grid, 8 squares are shaded blue. on the second 10 by 10 grid, 3 columns and 8 squares are shaded blue. part a write the multiplication expression shown by the model. do not solve the problem. part b explain the expression written in part a. include the final product and how it is shown with the model.