1) a) m+n

x=4+(-2)=2

y=-3+1=-2

m+n (2;-2)

b) m-n

x=4-(-2)=4+2=6

y=-3-1=-4

m-n (6;-4)

[tex] |n - m| = \sqrt{ {( - 2 - 4)}^{2} + {(1 - ( - 3))}^{2} } = \sqrt{ {( - 6)}^{2} + {4}^{2} } = \sqrt{36 + 16} = \sqrt{52} = \sqrt{13 \times 4} = 2 \sqrt{13} [/tex]

2) a-b

x=1-2=-1

y=1-2=-1

a-b (-1;-1)

a-b+c

x=-1+(-1)=-2

y=-1+1=0

a-b+c (-2;0)

3) BC=AD=c

CD=-AB=-a

AC=AB+BC=a+c

BD=BC+CD=c+(-a)=c-a