Question

11. The area of triangle is xy where x is length and y is breadth. If the length of rectangle is
increased by 5 units and breadth is decreased by 3 units, the new area of rectangle will be
(e) +5)-3)
12. The value of 2x (-3x) is
(6)-
(c)-5
13. Like terms in the expression 7x, 5x*, 7y, -5yx, -9x.are
(a) 7x, -5yx (b) 5x, -5yx
)- 6x
(d)7x 7
Ox
14. Area of rectangle of length šx' and breadth 5y is
(b) 15xy
(d)15y
15. Number of terms in the expression xyz + I is
3
(d)l​

Answer 1

Step-by-step explanation:

Let the length of the rectangle be x units and the breadth be y units.

Area of the rectangle=length×breadth

=x×y=xy sq. units

From the given information, we have,

(x+2)×(y−2)=xy−28

and(x−1)×(y+2)=xy+33

(x+2)×(y−2)=xy−28

=>xy−2x+2y−4=xy−28

=>−2x+2y=−24

=>−x+y=−12

=>x=y+12....(i)

Also,(x−1)×(y+2)=xy+33

=>xy+2x−y−2=xy+33

=>2x−y=35....(ii)

Substituting equation (i) in equation (ii), we get,

2x−y=35

=>2(y+12)−y=35

=>2y+24−y=35

=>y=11

Substituting y=11 in equation (i), we get,

x=y+12

=>x=11+12

=>x=23

Therefore, length of rectangle =x=23 units

and breadth of rectangle =y=11 units

Area of rectangle =xy=23×11=253 square units