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This lesson focuses on understanding square roots and solving radical equations effectively. It outlines essential steps, including isolating the radical, squaring both sides, solving the equation, and checking the solution for accuracy. Practice problems with detailed solutions are provided to reinforce concepts. This lesson is designed for students preparing for exams or seeking to enhance their algebra skills. Homework assignments are included to assess understanding and readiness for grading.
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ALGEBRA – LESSON 108 Square Roots, Radical Equations Be ready to grade the homework!
Grade Scale – 30 possible 29.5 – 98% 22.5 – 75% 29 – 97% 22 – 73% 28.5 – 95% 21.5 – 72% 28 – 93% 21 – 70% 27.5 – 92% 20.5 – 68% 27 – 90% 20 – 67% 26.5 – 88% 19.5 – 65% 26 – 87% 19 – 63% 25.5 – 85% 18.5 – 62% 25 – 83% 18 – 60% 24.5 – 82% 17.5 – 58% 24 – 80% 17 – 57% 23.5 – 78% 16.5 – 55% 23 – 77% 16 – 53%
Square Roots Whenever we want to “get rid” of a radical sign, we will square the radical. 4 Steps to remember: 1. Isolate the radical 2. Square both sides 3. Solve 4. Check
Square Roots – Just watch Solve: Öx – 2 – 6 = 0 Öx – 2 = 6 (Öx – 2)2 = 62 x – 2 = 36 x = 38 Check: Ö38 – 2 – 6 = 0 Ö36 – 6 = 0 6 – 6 = 0 x = 38
Square Roots – Just watch Solve: Öx2 + 9 – 5 = 0 Öx2 + 9 = 5 Ö42 + 9 = 5 (Öx2 + 9)2 = 52 Ö25 = 5 x = 4 x2 + 9 = 25 x2 = 16 Ö(-4)2 + 9 = 5 x2 – 16 = 0 (x + 4)(x – 4)= 0 Ö25 = 5 x = -4 x = -4 or 4
Square Roots Solve: Öx – 7 + 3 = -4 Öx – 7 = -7 (Öx – 7)2 = (-7)2 x – 7 = 49 x = 56 Check: Ö56 – 7 + 3 = -4 Ö49 + 3 = -4 7 + 3 = -4 #1 Empty set
Square Roots Solve: Öx – 6 + 8 = 2 Öx – 6 = -6 (Öx – 6)2 = (-6)2 x – 6 = 36 x = 42 Check: Ö42 – 6 + 8 = 2 Ö36 + 8 = 2 6 + 8 = 2 #2 Empty set
Square Roots Solve: Öe + 25 + 5 = e Ö0 + 25 + 5 = 0 Öe + 25 = e - 5 Ö25 + 5 = 0 (Öe + 25)2= (e - 5)2 Not a solution e + 25 = e2 – 10e + 25 Ö11 + 25 + 5 = 11 Ö36 + 5 = 11 0 = e2 – 11e e = 11 0 = e(e – 11) e = 0 or 11 #3
Square Roots Solve: Ö x – 1 – 3 + x = 0 Ö5 – 1 – 3 + 5 = 0 Ö x – 1 = 3 – x Ö4 + 2 = 0 (Ö x – 1)2= (3 – x)2 Not a solution x – 1 = 9 – 6x + x2 Ö2 – 1 – 3 + 2 = 0 Ö1 – 1 = 0 0 = x2 – 7x + 10 x = 2 0 = (x – 5)(x – 2) x = 5 or 2 #4
Square Roots Solve: Ö2x – 3 = Öx + 2 Ö2(5) – 3 = Ö5 + 2 Ö7 = Ö7 (Ö2x – 3)2= (Öx + 2)2 x = 5 2x – 3 = x + 2 x – 5 = 0 x = 5 #5
Homework: Worksheet
Square Roots Solve: 2Öx + 3x - 1 = 0 2 + 3 - 1 = 0 2Öx = -3x + 1 (2Öx )2= (-3x + 1)2 Not a solution 4x = 9x2 – 6x + 1 2(1/3) + 3(1/9) – 1 = 0 2/3 + 1/3 – 1 = 0 0 = 9x2 – 10x + 1 x = 1/9 Use Quadratic Formula x = 1 or 1/9 #4