GOODBAD VERY NOT Heres a trick to help you with the signs when you are multiplying two integers! + + - -
A picture of Madison that is 10cm by 15cm is going to have a matting of uniform width around it inside of its frame. Determine a simplified expression for the area of the glass needed to cover the picture and matting. 2x+10 2x+15
Area = length x width Area = (2x+10)(2x+15) To simplify algebraic expressions we use the distributive property. This means that we multiply everything inside of the second brackets by everything that is inside the first brackets!
Strategy #1 – Make a chart Area = (2x+10)(2x+15) 2x+10 2x +15 4x 2 +150 +30x +20x Area = 4x 2 +50x +150
Strategy #2 – Algebra Tiles Area = -x 2 x x -x +1 x x x x +1 x x x x x2x2 x2x2 x2x2 x2x2 x2x2 x2x2 x2x2 x2x2 x x x x x x x x x x x x x x x x x x x x (2x+3)(2x+2)
Strategy #3 – FOIL FO IL IRST UTSIDE NSIDE AST Area = (2x+10)(2x+15) Area = 4x 2 +30x+20x +150 Area = 4x 2 +50x+150