Use Identity 1A to write the expressions for the following. (i) (m + 3)² (ii) (6 + p)² Class 8
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Use Identity 1A to write the expressions for the following. (i) (m + 3)² (ii) (6 + p)² Class 8
Question 1.
Use Identity 1A to write the expressions for the following. Class 8
(i) (m + 3)2
(ii) (6 + p)2
Solution:
(i) (m + 3)2 = m2 + 2m × 3 + 32
= m2 + 6m + 9
(ii) (6 + p)2 = 62 + 2 × 6 × p + p2
= 36 + 122p + p2
Question 2.
Expand (3j + 2k)2 using both the identity and by applying the distributive property. Class 8
Solution:
(3j + 2k)2 = (3j)2 + 2(3j) (2k) + (2k)2
= 9j2 + 12jk + 4k2
or (3j + 2k)2 = (3j + 2k) + (3j + 2k)
= 3j (3j + 2k) + 2k (3j + 2k)
= 9j2 + 6jk + 6jk + 4k2
= 9j2 + 12jk + 4k2