140 likes | 325 Views
SLIDE SHOW INSTRUCTIONS This presentation is completely under your control. This lesson will show only one step at a time, to see the next step you must press a key. (Actual names written on a key are in green ) TO STOP THE SLIDE SHOW : press ‘escape’ ( Esc , top left of keyboard)
E N D
SLIDE SHOW INSTRUCTIONS • This presentation is completely under your control. • This lesson will show only one step at a time, • to see the next step you must press a key. • (Actual names written on a key are in green) • TO STOPTHE SLIDE SHOW: press ‘escape’ (Esc, top left of keyboard) • TO MOVE FORWARD: press the “spacebar” or Enter • (PageDn, , , also work) • TO MOVE BACKWARD: press the key • (PageUp, or also work)
Factoring Formulas • Difference of Two Squares • Cube Formulas • Trinomials: x2+bx+c • or x2+bxy+cy2 • 4. Perfect Square Trinomials
a b Answer Difference of Two Squares Use the formula: a2 - b2 = (a + b)(a - b) 1. Find a and b by taking the square root of each term. Example:x2 – 9 2. Place the numbers into the formula in the correct locations (x)2 - (3)2 = (x + 3)(x - 3) (replace the letter “a” in the formula with an “x”, replace the letter “b” with a “3”)
a b Answer Difference of Two Cubes Use the formula: a3 – b3 = (a - b)(a2 + ab + b2) 1. Find a and b by taking the cube root of each term. Example:x3 – 8 2. Place the numbers into the formula in the correct locations (x)3 - (2)3 = (x - 2)(x2 + 2x + 4) (replace the letter “a” in the formula with an “x”, replace the letter “b” with a “2”)
a b Answer Sum of Two Cubes Use the formula: a3 + b3 = (a + b)(a2 - ab + b2) 1. Find a and b by taking the cube root of each term. Example:x3 + 27 2. Place the numbers into the formula in the correct locations (x)3 + (3)3 = (x + 3)(x2 - 3x + 9) (replace the letter “a” in the formula with an “x”, replace the letter “b” with a “3”)
Practice Problems: (Hit enter to see the answers) Factor using the correct formula 1) x2 - 16 5) 27 + 8t3 2) a3 + 8 6) y2 + x2 3) 4x2 - 1 7) 9b2 - 4 4) x3- a3 8) 64x3- a3 Answers: 1) (x + 4)(x - 4) 2) (a + 2)(a2 - 2a + 4) 3) (2x + 1)(2x - 1) 4) (x - a)(x2+ ax + a2) 5) (3 + 2t)(9 - 6t + 4t2) 6) y2+ x2 (it doesn’t factor) 7) (3b + 2)(3b - 2) 8) (4x - a)(16x2+ 4ax + a2)
Trinomial of the form: x2 + bx + c 3. Make sure you have the correct signs: +2 and +4 = +6 1. Factor the last term: 2. Pick the pair or factors that when added together give you the middle term 1 + 8 = 9 2 + 4 = 6 1 * 8 2 * 4 4. Write these two numbers with an “x” in parentheses as follows, Answer: (x + 2)(x + 4) x2+ 6x+8 8
Trinomial of the form: x2 + bx - c 3. Make sure you have the correct signs: +3 and -2 = +1 1. Factor the last term: 2. Pick the pair or factors that when subtracted give you the middle term 6 - 1 = 5 3 - 2 = 1 1 * 6 2 * 3 4. Write these two numbers with an “x” in parentheses as follows, Answer: (x + 3)(x - 2) x2+ x-6 6
Trinomial of the form: x2 + bxy + cy2 3. Make sure you have the correct signs: +2 and +1 = +3 1. Factor the last term: (the coefficient only) 2. These factors when added together give you the middle term:1 + 2 = 3 1 * 2 4. Write these numbers with an “x” in the first position and a “y” in the second Answer: (x + 2y)(x + 1y) x2+ 3xy+ 2y2 2
Practice Problems: (Hit enter to see the answers) Factor these polynomials 1) x2 + 3x - 10 2) x2 + 2x - 3 3) a2 - 6a - 7 4) x2 - 5xy + 6y2 5) y2 - 5y - 6 6) 9 +6y + y2 Answers: 1) (x + 5)(x - 2) 2) (x + 3)(x - 1) 3) (a + 1)(a - 7) 4) (x - 3y)(x - 2y) 5) (y - 6)(y + 1) 6) (3 + y)(3 + y) Note: On problem #6, you can put the terms in the correct order before you try to factor them.
Perfect Square Trinomials +2ab a a2 b b2 (x + 3)2 = (x)2 + 2(x)(3) + (3)2 Formula (addition version): (a + b)2 = a2 + 2ab + b2 Find the product of (x + 3)2by plugging a and b into the formula (replace the letter a in the formula with x, and letter b with 3) = x2 + 6x + 9
+2ab a a2 b b2 (x - 5)2 = (x)2 - 2(x)(5) + (5)2 Perfect Square Trinomials Formula (subtraction version): (a - b)2 = a2 - 2ab + b2 Find the product (x - 5)2by plugging a and b into the formula (replace the letter a in the formula with x, and letter b with 5) = x2 - 10x + 25
Practice Problems: (Hit enter to see the answers) Use the correct formula to find the polynomial 1) (2x - 3)2 2) (a + 7)2 3) (4 - 2y)2 4) (x - y)2 Answers: 1) 4x2 -12x + 9 2) a2 + 14a + 49 3)16 - 16y + 4y2 4) x2 - 2xy + y2
End of Tutorial Go to www.greenebox.com for more great math tutorials for your home computer Questions? send e-mail to: lgreene1@satx.rr.com