Mathematics
If the point A(p, q) is first reflected in the y-axis and then reflected in the origin to the point A"(-6, 15), then the value of (2p + 3q) is :
-57
-21
43
57
Reflection
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Answer
Given, point A(p, q).
On reflection in y-axis, the sign of x-coordinate changes,
(p, q) ⇒ (-p, q)
On reflection in origin, the sign of x-coordinate and y-coordinate changes,
(-p, q) ⇒ (p, -q).
Given,
Final coordinates = A"(-6, 15)
∴ (p, -q) = (-6, 15)
⇒ p = -6 and -q = 15
⇒ p = -6 and q = -15
⇒ 2p + 3q = 2(-6) + 3(-15)
= -12 - 45
= -57.
Hence, Option 1 is the correct option.
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