Given:
2(a2+ab)+3-ab
⇒ 2a2+2ab+3-ab
⇒ 2a2+2ab-ab+3
⇒ 2a2+ab+3
⇒ 2(5)2+(5)(-3)+3
⇒ 2×25-15+3 [putting a=5, b=-3]
⇒ 50-15+3
⇒ 38
Match the items given in Column I with one or more items of Column II.
Column I | Column II |
(a) A plane mirror | (i) Used as a magnifying glass. |
(b) A convex mirror | (ii) Can form image of objects spread over a large area. |
(c) A convex lens | (iii) Used by dentists to see enlarged image of teeth. |
(d) A concave mirror | (iv) The image is always inverted and magnified. |
(e) A concave lens | (v) The image is erect and of the same size as the object. |
- | (vi) The image is erect and smaller in size than the object. |