Answer:
x = 5.5
y = - 6.5
Step-by-step explanation:
Let one of the numbers = x
Let the other number = y
x + y = - 1
x = y + 12 Put the second equation into the first one
y + 12 + y = - 1 Subtract 12 from both sides
y + y = - 1 - 12 Combine both left and right sides
2y = - 13 Divide by 2
2y/2 = - 13/1
y = - 6.5
x + y = - 1
x - 6.5 = - 1 Add 6.5 to both sides
x = 5.5
They're allowed to join for $15. And for every event, they have to pay $3.
3x = 21
x = 7
Someone who has $36 can attend 7 events.
Option B:

Solution:
In the given figure
.
If two triangles are similar, then their corresponding sides and angles are equal.
By CPCTC, in
,
– – – – (1)
– – – – (2)
– – – – (3)
– – – – (4)
– – – – (5)
– – – – (6)
Option A: 
By CPCTC proved in equation (2)
.
Therefore
. Option A is false.
Option B: 
By CPCTC proved in equation (1)
.
Therefore Option B is true.
Option C: 
By CPCTC proved in equation (4)
.
Therefore
. Option C is false.
Option D: 
By CPCTC proved in equation (5)
.
Therefore
. Option D is false.
Hence Option B is the correct answer.

The answers would be letter b