If you don't double check your answers by substituting them back into the original equation, you may be introducing extraneous solutions into the problem which is why you should always check to confirm your answer is accurate. I hope this helps! :)
Answer:
You would use the formula: Rate = distance / time which equals 55
Since we are asked for the time it takes to reach 3/4 the destination.We just use 3/4 of the value of the distance.
55 = (3/4)(440) / t
t = 6 hours
So the answer would be "C"
$30 + $35 = $65
Assuming tax is on whole sale not each item:
$65 * 0.06 (6%) = $3.90 (6% of $65)
$65 + $3.90 = $68.90 ($65 + 6%)
OR
You could combine both of these steps and just use this working:
$65 * 1.06 (106%) = $68.90 (106% of $65)
Y = 3x - 7...slope here is 3 and y int is -7
3x + 9y = 9
9y = -3x + 9
y = -1/3x + 1....slope here is -1/3 and y int is 1
the slopes 3 and -1/3 are negative reciprocals of each other...therefore, ur lines are perpendicular
