Answer: 0 and 1, in that order
The numbers <u> 0 </u> and <u> 1 </u> are respectively the additive and multiplicative identities of rational numbers.
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Explanation:
The additive identity is 0 because adding 0 to any number leads to the original number. For instance, 7+0 = 7. In general we can say x+0 = x or we could also say 0+x = x.
The multiplicative identity is 1 because multiplying 1 with anything leads to that original number. Example: 1*5 = 5 or 9*1 = 1. The general template is x*1 = x which is the same as saying 1*x = x.
These ideas not only apply to rational numbers, but to real numbers as well.
The minimum distance will be along a perpendicular line to the river that passes through the point (7,5)
4x+3y=12
3y=-4x+12
y=-4x/3+12/3
So a line perpendicular to the bank will be:
y=3x/4+b, and we need it to pass through (7,5) so
5=3(7)/4+b
5=21/4+b
20/4-21/4=b
-1/4=b so the perpendicular line is:
y=3x/4-1/4
So now we want to know the point where this perpendicular line meets with the river bank. When it does y=y so we can say:
(3x-1)/4=(-4x+12)/3 cross multiply
3(3x-1)=4(-4x+12)
9x-3=-16x+48
25x=51
x=51/25
x=2.04
y=(3x-1)/4
y=(3*2.04-1)/4
y=1.28
So now that we know the point on the river that is closest to Avery we can calculate his distance from that point...
d^2=(x2-x1)^2+(y2-y1)^2
d^2=(7-2.04)^2+(5-1.28)^2
d^2=38.44
d=√38.44
d=6.2 units
Since he can run at 10 uph...
t=d/v
t=6.2/10
t=0.62 hours (37 min 12 sec)
So it will take him 0.62 hours or 37 minutes and 12 seconds for him to reach the river.
At least means it can be larger than or equal to.
X >= 15
No more than means less than or equal to:
X <= $7