Question 2 - Figure it out - Page 142, 143 - Chapter 6 Class 8 - We Distribute yet things Multiply (Ganita Prakash)

Transcript

Question 2 (i) Expand the following products. (3 + u) (v – 3)Solving (3+u)(𝑣−3) =3(𝑣−3)+𝑢(𝑣−3) =3 × 𝑣+3 × (−3) +𝑢 × 𝑣+𝑢 × (−3) =3𝑣−9+𝑢𝑣−3𝑢 =𝟑𝒗−𝟑𝒖+𝒖𝒗−𝟗 Question 2 (ii) Expand the following products. 2/3 "(15 + 6a)" Solving 2/3(15+6a) =2/3 × 15+2/3 × 6𝑎 =2 × 5+2 × 2𝑎 =𝟏𝟎+𝟒𝐚 Question 2 (iii) Expand the following products. (10a + b) (10c + d)Solving (10a+b)(10𝑐+𝑑) =10𝑎(10𝑐+𝑑)+𝑏(10𝑐+𝑑) =10𝑎 × 10𝑐+10𝑎 × 𝑑+𝑏 × 10𝑐+𝑏 × 𝑑 =10 × 10 × 𝑎𝑐+10𝑎𝑑+10𝑏𝑐+𝑏𝑑 =𝟏𝟎𝟎𝒂𝒄+𝟏𝟎𝒂𝒅+𝟏𝟎𝒃𝒄+𝒃𝒅 Question 2 (iv) Expand the following products. (3 – x) (x – 6)Solving (3−𝑥)(𝑥−6) =3(𝑥−6)−𝑥(𝑥−6) =3 × 𝑥+3 × (−6) +(−𝑥) × 𝑥+(−𝑥) × (−6) =𝟑𝒙−𝟏𝟖−𝒙^𝟐+𝟔𝒙 =(3𝑥+6𝑥)−18−𝑥^2 =9𝑥−18−𝑥^2 =−𝒙^𝟐+𝟗𝒙−𝟏𝟖 Question 2 (v) Expand the following products. (–5a + b) (c + d)Solving (−5𝑎+𝑏)(𝑐+𝑑) =−5𝑎(𝑐+𝑑)+𝑏(𝑐+𝑑) =−5a × 𝑐+(−5𝑎) × 𝑑+𝑏 × 𝑐+𝑏 × 𝑑 =−𝟓𝒂𝒄−𝟓𝒂𝒅+𝒃𝒄+𝒃𝒅 Question 2 (vi) Expand the following products. (5 + z) (y + 9)Solving (5+𝑧)(𝑦+9) =5(𝑦+9)+𝑧(𝑦+9) =5 × 𝑦+5 × 9 +𝑧 × 𝑦+𝑧 × 9 =𝟓𝒚+𝟒𝟓+𝒛𝒚+𝟗𝒛