Answer:
x = 17, MN = 11
Step-by-step explanation:
Given 2 secants from an external point to a circle, then
The product of the external part and the whole of one secant is equal to the product of the external part and the whole of the other secant.
(5)
7(7 + x) = 8(8 + 13) = 8 × 21 = 168 ( divide both sides by 7 )
7 + x = 24 ( subtract 7 from both sides )
x = 17
(6)
9(9 + 2x - 7) = 10(10 + 8)
9(2x + 2) = 10 × 18 = 180 ( divide both sides by 9 )
2x + 2 = 20 ( subtract 2 from both sides )
2x = 18 ( divide both sides by 2 )
x = 9
Then
MN = 2x - 7 = 2(9) - 7 = 18 - 7 = 11
The length of OM is 4/3 the length of OJ, and the length of ON is 4/3 the length of OK. Thus, two pairs of sides from the triangles are proportional to each other.
Also, angle O from one of the triangles is equal to angle O of the other triangle because they are the same angle.
Thus, the two triangles are similar by SAS (side-angle-side) similarity theorem. This theorem is quite similar to the SAS congruence theorem.
To make a similarity statement, we just have to match corresponding parts when naming the triangle.
Similarity statement: ΔOJK~ΔOMN
Let x = times in the pool
Let y = times in the basketball courts
42=3x+5y
x+y=12
Therefore y = 12-x
Subsitute for y
42 = 3x + 5(12-x)
42 = 3x + 60 -5x
Subtract 60
-18 = -2x
9 = x
The person used the pool 9 times.
Answer:

point slope form....
y - (-7) = -1/2(x-4)
y + 7 = -x/2 + 2
2y + 14 = -x + 4
2y = -x -10
y = -1/2 x - 5
Step-by-step explanation:
Answer:
X= 1/2 Y= 5
Step-by-step explanation:
8x+7y=39-------------(1)--------×2
4x-14y= -68-----------(2)-------×1
16X + 14Y = 78--------(3)
4X- 14Y = -68----------(4)
Addy equation (4) and (3)
20X = 10
dividing bothsides by 20
20X/20= 10/20
X = 1/2
substitute the value of X into equation (1)
8X+7Y = 39
8(1/2)+7Y= 39
4+7Y = 39
7Y = 39-4
7Y = 35
dividing bothsides 7
7Y= 35/7
Y = 5