GSEB Solutions for Class 8 Mathematics – Revision 2 (Sem – II) (English Medium)
GSEB SolutionsMathsScience
Revision 2
Solution 1:
Solution 2A:
Solution 2B:
- ab3 + ab= ab(b2 + 1)
- x3 – 5x2 + 2x – 10= x2(x – 5) + 2(x – 5)= (x – 5)(x2 + 2)
- 4a2b2 + 4ab + 1= (2ab)2 + 2(2ab)(1) + (1)2= (2ab + 1)2
- 4x2 + 9y2 + 25z2 + 12xy + 30yz + 20zx= (2x)2 + (3y)2 + (5z)2 + 2(2x)(3y) + 2(3y)(5z) + 2(5z)(2x)= (2x + 3y + 5z)2
- m4 – 8m2 + 16= (m2)2 – 2(m2)(4) + (4)2= (m2 – 4)2
- 64m3 – mn2 = m(64m2 – n2) = m[(8m)2 – (n)2] = m(8m + n)(8m – n)
- 4x2 + 4x + 1 – y2 + 10y – 25= (4x2 + 4x +1 ) – (y2 – 10y + 25)= (2x + 1)2 – (y – 5)2
= m2 – n2 (Taking 2x + 1 = m and y – 5 = n)= (m + n)(m – n)
= [(2x + 1) + (y – 5)][(2x + 1) – (y – 5)] (Putting back m = 2x + 1 and n = y – 5)
= (2x + 1 + y – 5)(2x + 1 – y + 5)
= (2x + y – 4)(2x – y + 6) - 4x4 – 12x2 + 9= (2x2)2 – 2(2x2)(3) + (3)2= (2x2 – 3)2
Solution 3A(1):
Solution 3A(2):
Solution 3B(1):
Solution 3B(2):
Solution 3B(3):
Solution 3B(4):
solution 4(1):
Solution 4(2):
Solution 4(3):
Solution 5(1):
Solution 5(2):
Solution 5(3):
Solution 5(4):