Class 8, Maths, Chapter 14, Exercise 14.4 Solutions
Find and correct the errors in the following mathematical statements.
Q.1. 4(x – 5) = 4x – 5
Q.2. x(3x + 2) = 3×2 + 2
Q.3. 2x + 3y = 5xy
Q.4. x + 2x + 3x = 5x
Q.5. 5y + 2y + y – 7y = 0
Q.6. 3x + 2x = 5x2
Q.7. (2x)2 + 4(2x) + 7 = 2x2 + 8x + 7
Q.8. (2x)2 + 5x = 4x + 5x = 9x
Q.9. (3x+2)2 = 3x2 + 6x + 4
Q.10. Substituting x = –3 in
(a) x2+5x+4 gives (–3)2+5(–3)+4 = 9+2+4=15
(b) x2–5x+4 gives (–3)2–5(–3)+4= 9 – 15 + 4 =–2
(c) x2 + 5x gives (–3)2+ 5(–3) =–9 –15 =–24
