Answer:
Step-by-step explanation:
Let the length and breadth of the rectangle be a,b units respectively.
Then the area will be ab square units.
Now if the length of the rectangle is reduced by 5 units and breadth is increased by 2 units then new length and breadth will be (a−5) units and (b+2) units.
Then new area will be (a−5)(b+2).
Then according to the problem,
(a−5)(b+2)−ab=−80
or, 2a−5b=−70.......(1).
Now if length of the rectangle is increased by 10 units and breadth is decreased by 5 units then new length and breadth will be (a+10) units and (b−5) units.
Then new area will be (a+10)(b−5).
Then according to the problem,
(a+10)(b−5)−ab=50
or, 10b−5a=100
or, 2b−a=20
or, 4b−2a=40......(2).
Now adding (1) and (2) we get
−b=−30
or, b=30.
Putting the value of b in (1) we get, a=40.
Now a+b=40+30=70.
Answer:
4pi
Step-by-step explanation:
The area of a circle is given by
A = pi r^2
where r is the radius
The radius of a circle is found by
r =d/2 where d is the diameter
r = 4/2 = 2
So A = pi (2)^2
pi (4)
4pi
Answer:
-50
Step-by-step explanation:
b-5
b-5 = -45 ( collect like terms)
b = -45 + -5
b = -45 -5 b = -50