Page 147 - ICSE Math 8

2
2
4. What must be subtracted from 3a + 2a – 5 to get 9a – 3a + 2?
2
2
2
2
5. The length and breadth of a rectangle are (2l – 5lm + 3n ) units and (4l + 2lm – 2n ) units. Find its
perimeter.
2
2
2
2
6. The adjacent sides of a rectangle are (5x – 8xy + 6y ) units and (x – 5xy + 2y ) units. Find its area.
3
7. The area of a rectangle is (27p – 1) sq. units and its breadth is (3p – 1) units. Find its length.
4
x – y 4
3
2
2
3
8. Show that = x + x y + xy + y .
x – y
9. Simplify the following.
(a) –[x – {y + (y – x) – (x – y) – x} – y] (b) 2(3y – 2x) – 5[x – 4{2 – 3(x – y)}]
10. Peter has ‘R’ red marbles and ‘B’ blue marbles. Sam has half as many red marbles and 5 less blue marbles
than peter. Write an algebraic expression to represent Sam’s total number of marbles.
THINK SMART
1. The figure shows the dimensions of a wall having a window and 5x + 2
a door of a room. Write an algebraic expression for the area of the
wall to be painted and the cost of painting the wall at the rate of Door 2x
` 569 per sq. unit. x 5x
–1
2. A hot air balloon flies at a speed of (x + 8) km h . At this rate, how 3x Window
2
long will it take the balloon to fly (x + 5x – 24) km?
x

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