Answer:

Step-by-step explanation:
Given
The attached graph
Required

This is the point where

On the attached graph;
when 
Hence:

The angles inside a triangle are called interior angles. The diagram below shows the interior and exterior angles of a triangle. The three interior angles in a triangle will always add up to 180°. At each corner the exterior and interior angles are on a straight line, so at each corner these two angles add up to 180°.
Answer:
20
Step-by-step explanation:
2(6+4)=
2*10=
20
Answer : the answer is 5 people per T-shirt
Step-by-step explanation: because its 5 people per 1 T-shirt
Rearranging the first equation gives:

Substituting this into the other equation gives:

If x=-1:

So
x=-1, y=-5