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5cm. 2cm. Find the area of these rectangles. 63 cm 2. 3 cm. 10 cm 2. 21 cm. 8 cm. 6 cm. 8x + 16 cm 2 or 8(x + 2) cm 2. 6x cm 2. x cm. x + 2 cm. x cm. 2x 2 + x cm 2 or x(2x + 1) cm 2. 2x + 1 cm. L.O. – To be able to expand brackets of the form (2x + 3)(3x – 5)
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5cm 2cm Find the area of these rectangles 63 cm2 3 cm 10 cm2 21 cm 8 cm 6 cm 8x + 16 cm2 or 8(x + 2) cm2 6x cm2 x cm x + 2 cm x cm 2x2 + x cm2 or x(2x + 1) cm2 2x + 1 cm
L.O. – To be able to expand brackets of the form (2x + 3)(3x – 5) To be able to expand brackets of the form (3x + y + 2)(2x + 9)
How do we expand (x+1)(x+3)? x + 3 1 1 1 x x x2 x x x x + 1 1 1 1 1 x Area = x2 + 4x + 3
The simpler way to expand (x+1)(x+3) (x + 1)(x + 3) = x2 + 3x + x + 3 = x2 + 4x + 3
And it even works with negative numbers! (x + 4)(x - 2) = x2 - 2x + 4x - 8 = x2 + 2x -8
Try these examples: Don’t be afraid to draw on the arrows if it helps (x + 2)(x + 5) = x2 + 7x + 10 x2 – 5x – 24 x2 + x - 20 x2 + 4x + 4 (x + 3)(x - 8) = (x – 4)(x + 5) = (x + 2)2 = (2x + 1)(x + 4) = (x+2)(x+2) =
How to solve (2x + 1)(x + 4) (2x + 1)(x + 4) = 2x2 + 8x + x + 4 = 2x2 + 9x + 4
Now try these examples 6x2 + 14x + 4 (2x + 4)(3x + 1) = 5x2 + 17x + 6 12x2 + 7x - 10 24x2 - 31x + 10 (5x + 2)(x + 3) = (4x + 5)(3x - 2) = (3x - 2)(8x – 5) = (2x + y + 1)(3x + 2) = 6x2 + 3xy + 7x +2y + 2
Now pick one of the following to solve.Your partner will mark it in a couple of minutes (4x + 3)(2x + 5) = (3x -7)(5x + 2) = (6x + 4)(2x – 3) = 8x2 + 26x + 15 15x2 -29x - 14 12x2 - 10x -12