Well area of a triangle is

so,

The answer is 8
(11 + 21) - ( 3 - 100 )
= 32 + 97
= 129
or (11+21)-(3+100)
= 32 - 103
= - 71
I have no idea about your topic but hope it's right! Good luck
Answer:
y= -2x+1
Step-by-step explanation:
y=mx+b
y= -2x +b
3= -2(1) +b
3= -2 +b
b=1
y= -2x+1