1
:x
2
+y
2
−6x−9y+13=0
(x−3)
2
+(y−
2
9
)
2
−9−
4
81
+13=0
(x−3)
2
+(y−
2
9
)
2
=
4
65
Here,
r
1
=
2
65
C
1
=(3,
2
9
)
Equation of another circle-
S
2
:x
2
+y
2
−2x−16y=0
(x−1)
2
+(y−8)
2
−1−64=0
(x−1)
2
+(y−8)
2
=65
Here,
r
2
=
65
C
2
=(1,8)
Distance between the centre of two circles-
C
1
C
2
=
(3−1)
2
+(8−
2
9
)
2
C
1
C
2
=
4+
4
49
=
2
65
∣r
2
−r
1
∣=
∣
∣
∣
∣
∣
∣
65
−
2
65
∣
∣
∣
∣
∣
∣
=
2
65
∵C
1
C
2
=∣r
1
−r
2
∣
Thus the two circles touches each other internally.
Since the circle touches each other internally. The point of contact P divides C
1
C
2
externally in the ratio r
1
:r
2
, i.e.,
2
65
:
65
=1:2
Therefore, coordinates of P are-
⎝
⎜
⎜
⎜
⎜
⎜
⎛
1−2
1(1)−2(3)
,
1−2
1(8)−2(
2
9
)
⎠
⎟
⎟
⎟
⎟
⎟
⎞
=(5,1)
Therefore,
Equation of common tangent is-
S
1
−S
2
=0
(5x+y−6(
2
x+5
)−9(
2
y+1
)+13)−(5x+y−2(
2
x+5
)−16(
2
y+1
))=0
2
−6x−9y−13
+x+8y+13=0
4x−7y−13=0
Hence the point of contact is (5,1) and the equation of common tangent is 4x−7y−13=0.
The best way to work this out is to find the total number, minus the remained. In this case, subtract four from 196, and this gives you 192. As you've got to put the pencils into 8 boxes, you have to divide 192 by 8, and this gives you 24.
Therefore, Soni can put 24 pencils can be put into each box, with four pencils remaining.
Hope this helps :)
Answer:
<em>The man paid $200 for the cow</em>
Step-by-step explanation:
<u>System of Equations</u>
Let's call:
x = price of the cow
y = price of the horse
The man bought the cow and the horse for $500, thus
x + y = 500 [1]
The cow was sold at a profit of 10%, thus:
Sale price of the cow= 1.1x
The horse was sold at a loss of 10%, thus:
Sale price of the horse= 0.9y
The total operation was a 2% loss, i.e. 0.98*500=490. Thus, we have:
1.1x + 0.9y = 490 [2]
From [1]:
y = 500 - x
Substituting in [2]:
1.1x + 0.9(500 - x) = 490
Operating:
1.1x + 450 - 0.9x = 490
0.2x = 490 - 450 = 40
x = 40/0.2
x = 200
The man paid $200 for the cow
Answer:
-1 -3i
Step-by-step explanation:
It is unusual to have two imaginary terms grouped together like this. Taking the question at face value, we treat i as though it were a variable, and collect terms in the usual way.
(-2i +3i) +(-1 -4i) = i(-2+3-4) -1 = -1 -3i
