## Algebra 1

a) $(1,2), (8,2), (3,4)$ b) Please see the graph, 7 square units
a) $x-y=-1$ $y=2$ $-.4x-y=-5.2$ $x-y=-1$ $y=2$ $x-2=-1$ $x-2+2=-1+2$ $x= 1$ $(1,2)$ is a point $y=2$ $-.4x-y=-5.2$ $-.4x-2=-5.2$ $-.4x-2+2 = -5.2+2$ $-.4x = -3.2$ $-.4x/-.4 = -3.2/-.4$ $x = 8$ $(8,2)$ is a point $x-y=-1$ $-.4x-y=-5.2$ $x-y=-1$ $x = y-1$ $-.4x-y=-5.2$ $-.4(y-1)-y=-5.2$ $-.4y+.4-y = -5.2$ $-1.4y+.4=-5.2$ $-1.4y+.4-.4=-5.2-.4$ $-1.4y = -5.6$ $-1.4y/-1.4 = -5.6/-1.4$ $y = 4$ $x-y=-1$ $x-4=-1$ $x-4+4=-1+4$ $x=3$ $(3,4)$ is a point b) Distance of base determined from points on line $x=2$. The two points are $(1,2)$ and $(8,2)$. ($8-1=7$, the base) Height determined from distance $(3,4)$ is from $y=2$, which is 2 ($4-2=2$). $7*2*1/2 = 7$ square units