A.
lxl=7
x=7 x=-7 (Take two cases, one as the others side negative and the other as positive)
B.
l2xl=32
2x=32 2x=-32
x=16 x=-16
C.
lx+7l=10
x+7=10 x+7=-10
x=3 x=-17
D.
lxl=53.1
x=53.1 x=-53.1
The coordinates of points A, B, and C are (5, 4), (–2, 1), and (4, –4), respectively. Which point, B or C, is closer to point A?
Elena-2011 [213]
Answer:
The distance between two points (x1,y1) and (x2,y2) = √((x1-x2)2+(y1-y2)2) Distance between A and B = √((5--2)2+(4-1)2) = √(72+32) = √(49+9) = √58 = 7.62 Distance between A and C = √(12+82) = √65 = 8.06 Point B is closer to A. Another method to solve this problem is to draw the points on a graph paper and measure distance with a ruler.
Answer:
59
Step-by-step explanation:
It's quite simple. A triange has a total of 180 degress. So add 47 and 74 to get 121. Then do 180 minus 121 to get 59
X represents the amount of weeks:
7+x for Germany and 3+2x for Tony they have to be equal for them to run the same distance:
3+2x=7+x
-3 from each side:
2x=4+x
-x from each side:
x=4
They run the same distance on the fourth week, that distance is 7+4=11
Hope this helps :)
The first time I did it, I got an answer that's not one of the choices. The second time
I did it, I got an answer that IS . Here are both of my procedures. If all you want is
the answer, look down below at the second one. But if you could help me out, now
that you know how to do this stuff, please look at my first solution and tell me where
I messed up. I can't find it.
=======================================================
Here's what the problem tells you:
D = 10 log ( ' I ' / 10⁻¹² )
D = 60 . . . . . find ' I ' .
Here we go:
60 = 10 log ( ' I ' / 10⁻¹² )
Divide each side by 10 :
6 = log ( ' I ' / 10⁻¹² )
Raise 10 to the power of each side of the equation:
10⁶ = ' I ' / 10⁻¹²
Multiply each side by 10¹² :
10¹⁸ = ' I ' That's 10^18. It looks bad, because that isn't one of the choices.
Let's try a slightly different procedure:
============================================
After substituting 10⁺¹² for I₀ , we're working with this formula:
D = 10 log ( 'I' / 10⁺¹² )
Let's just look at the log part of that.
The log of a fraction is [ log(numerator) - log(denominator) ]
log of this fraction is [ log( 'I' ) - log(10⁻¹²) ]
But log(10⁻¹²) is just (-12) .
So the log of the fraction is [ log( 'I' ) + 12 ]
And the whole formula is now:
D = 10 [ log( 'I' ) + 12 ]
60 = 10 [ log( 'I' ) + 12 ]
Divide each side by 10 :
6 = log( 'I' ) + 12
Subtract 12 from each side :
-6 = log ( ' I ' )
' I ' = 10⁻⁶
That's choice-'B' .
==================================================
I'm going to leave the first solution up there, in hopes that you, or one
of the many aces, experts, and geniuses that prowl this site constantly,
can weigh in and show me my blunder on the first attempt.
