-5.8 + (-2.5) = -8.3
since both the number are negative you simply add the numbers and use the negative sign.
Answer: D
Work is shown in picture :)
Answer: $11.80 for another 4 panes of glass.
Step-by-step explanation: We know that 9 panes of glass cost $26.55, but we should first find how many dollars would it cost per pane of glass, or 1.
So, we can divide 26.55 by 9 to find the price per 1 pan of glass.
26.55/9 = 2.95, or $2.95 per pane of glass.
Now, we want to know how much it will cost for 4 panes of glass. Simply multiply 2.95 by 4.
2.95 x 4 = 11.8, or $11.80 for another 4 panes of glass.
(4,5)(2,1)
slope = (1 - 5) / (2 - 4) = -4/-2 = 2
(-2,3)(-4,4)
slope = (4 - 3) / (-4 - (-2) = 1/(-4 + 2) = -1/2
2 and -1/2 are negative reciprocals of each other....therefore, ur lines are perpendicular <==