Last updated at Dec. 16, 2024 by Teachoo
Question 5 Show that. (i) (3𝑥+7)^2−84𝑥=(3𝑥−7)^2 Solving LHS (3𝑥+7)^2−84𝑥 = (3𝑥)^2+(7)^2+ 2(3𝑥)(7)−84𝑥 = 9𝑥^2+49+42𝑥−84𝑥 = 9𝑥^2+49−42𝑥 (𝑎+𝑏)^2=𝑎^2+𝑏^2−2𝑎𝑏 Putting 𝑎 = 3𝑥 & 𝑏 = 7 = (3𝑥)^2+(7)^2+ 2(3𝑥)(7)−84𝑥 = 9𝑥^2+49+42𝑥−84𝑥 = 9𝑥^2+49−42𝑥 Solving RHS (3𝑥−7)^2 (𝑎−𝑏)^2=𝑎^2+𝑏^2−2𝑎𝑏 Putting 𝑎 = 3𝑥 & 𝑏 = 7 = (3𝑥)^2+(7)^2−2(3𝑥)(7) = (3^2×𝑥^2 )+49−(2×3×7)𝑥 = 9𝑥^2+49−42𝑥 Thus LHS = RHS Hence proved
Algebra Identities and Formulas
Question 1 (ii) Important
Question 1 (iii)
Question 1 (iv)
Question 1 (v) Important
Question 1 (vi) Important
Question 1 (vii)
Question 1 (viii)
Question 1 (ix) Important
Question 1 (x)
Question 2 (i)
Question 2 (ii)
Question 2 (iii)
Question 2 (iv) Important
Question 2 (v)
Question 2 (vi) Important
Question 2 (vii) Important
Question 3 (i)
Question 3 (ii) Important
Question 3 (iii)
Question 3 (iv) Important
Question 3 (v) Important
Question 3 (vi)
Question 4 (i)
Question 4 (ii)
Question 4 (iii) Important
Question 4 (iv)
Question 4 (v) Important
Question 4 (vi)
Question 4 (vii) Important
Question 5 (i) You are here
Question 5 (ii)
Question 5 (iii) Important
Question 5 (iv)
Question 5 (v) Important
Question 6 (i)
Question 6 (ii) Important
Question 6 (iii)
Question 6 (iv)
Question 6 (v) Important
Question 6 (vi)
Question 6 (vii) Important
Question 6 (viii)
Question 6 (ix) Important
Question 7 (i)
Question 7 (ii) Important
Question 7 (iii)
Question 7 (iv) Important
Question 8 (i)
Question 8 (ii)
Question 8 (iii) Important
Question 8 (iv) Important
About the Author
Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo