Hello :
the normal vector of the plane is : d' = [4,-1,5]...(vector perpendicular to the plane)<span>
d </span><span>⊥ d' because : (4)(2)+(-1)(3)+(5)(1)=0
</span>the line is perpendicular to the plane .
Let’s call the speed of the slower car S, then the speed of the other is S+10mph.
At 5pm they have been travelling for 3 hours. The slower car travels a distance 3S and the faster one 3(S+10).
But the two distances must add up to 240 miles so 3S+3(S+10)=240, 3S+3S+30=240, 6S=210, S=35 mph. The faster car’s speed is 45mph. We can see that 3S is the same distance as 3x, so x=S=35 mph, and the distance the faster car travels is 3×45=135 miles.
If we solve the left side of the given equation,
1/a + 1/b = 1/c
we get an answer of,
b+a / ab = 1/c
Since ab = c, we can conclude that b + a is 1. The average of these two numbers is equal to there sum divided by 2. The answer is therefore equal to 0.5.
Monday and Tuesday are the correct answers due to the negative number being lower than -1.75 F
