Question

1.(a+2b-c)²
2.(x- 2y+2z)²
3.(-a-b-c)²
4.(2a+3b+c)²​

Answer 1

Answer:

(i) (a + 2b + c)2 = a2 + (2b)2 + c2 + 2a(2b) + 2ac + 2(2b)c = a2 + 4b2 + c2 + 4ab + 2ac + 4bc (ii) (2a − 3b − c)2 = [(2a) + (−3b) + (−c)]2 = (2a)2 + (−3b)2 + (−c)2 + 2(2a)(−3b) + 2(−3b)(−c) + 2(2a)(−c) = 4a2 + 9b2 + c2 − 12ab + 6bc − 4ca (iii) (−3x+y+z)2 = [(−3x)2 + y2 + z2 + 2(−3x)y + 2yz + 2(−3x)z = 9x2 + y2 + z2 − 6xy + 2yz − 6xz (iv) (m+2n−5p)2 = m2 + (2n)2 + (−5p)2 + 2m × 2n + (2×2n×−5p) + 2m × −5p = m2 + 4n2 + 25p2 + 4mn − 20np − 10pm (v) (2+x−2y)2 = 22 + x2 + (−2y)2 + 2(2)(x) + 2(x)(−2y) + 2(2)(−2y) = 4 + x2 + 4y2 + 4 x − 4xy − 8y