What about the second activity? Did you pick out the correct tiles? 5x + 3x Get five (+x tiles) and three more (+x) tiles. How many do you have in all? There are eight (+x) altogether. Therefore, 5x + 3x = 8x. (3x - 4) - 6x Get three (+x) tiles and four (-1) tiles to represent (3x - 4). Add six (-x) tiles. [Recall that subtraction also means adding the negative of the quantity.] Now, recall further that a pair of one (+x) and one (-x) is zero. What tiles do you have left? if you have with you three (-x) and four (-1), then you are correct. That’s right, That means the sum is (-3x -4). (2x2 5x + 2) + (3x2 + 2x) –
What about the second activity? Did you pick out the correct tiles? 5x + 3x Get five (+x tiles) and three more (+x) tiles. How many do you have in all? There are eight (+x) altogether. Therefore, 5x + 3x = 8x. (3x - 4) - 6x Get three (+x) tiles and four (-1) tiles to represent (3x - 4). Add six (-x) tiles. [Recall that subtraction also means adding the negative of the quantity.] Now, recall further that a pair of one (+x) and one (-x) is zero. What tiles do you have left? That’s right, if you have with you three (-x) and four (-1), then you are correct. That means the sum is (-3x -4). (2x2 – 5x + 2) + (3x2 + 2x)
7-math-lm_mod3.docx