B is the correct answer. hope this helped:)
-2/3-(-1 1/3) =
-2/3 + 1 1/3 =
4/3 - 2/3 =
<em>2/3</em>
12 - (-5) =
12 + 5 =
<em>17</em>
-1 - (-6) =
-1 + 6 =
6 - 1 =
<em>5</em>
-3 3/8 - 7/8 =
27/8 - 7/8 =
20/8 =
2 4/8 =
<em>2</em><em> </em><em>1/2</em>
Multiply the first equation with (-1)
you should get this
-6r + 3t = -6
6r + 8t = -16
start to eliminate
11t = -22
divide by 11
t = -2
substitute
6r - 3(-2) = 6
6r + 6 = 6
6r = 6 - 6
6r = 0
r=0