Mathematics
When x = 4 and y = 2, find the value of:
(i) x + y
(ii) x - y
(iii) x2 + 2
(iv) x2 - 2xy + y2
Answer
Given, x = 4 and y = 2.
(i) Substituting x = 4 and y = 2 in x + y, we get:
x + y = 4 + 2
∴ x + y = 6
(ii) Substituting x = 4 and y = 2 in x - y, we get:
x - y = 4 - 2
∴ x - y = 2
(iii) Substituting x = 4 in x2 + 2, we get:
x2 + 2 = (4)2 + 2
= 4 × 4 + 2
= 16 + 2
∴ x2 + 2 = 18
(iv) Substituting x = 4 and y = 2 in x2 - 2xy + y2, we get:
x2 - 2xy + y2 = (4)2 - 2(4)(2) + (2)2
= 16 - 16 + 4
= 4
∴ x2 - 2xy + y2 = 4
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