I did my math on a piece of paper but the answer would be x= 107/96
well there is -4 which is the oppsite of positive 4 if that what you ment
5x + 2y = 6
3x + y = 4....multiply by -2
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5x + 2y = 6
-6x - 2y = -8 (result of multiplying by -2)
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-x = -2
x = 2
5x + 2y = 6
5(2) + 2y = 6
10 + 2y = 6
2y = 6 - 10
2y = -4
y = -4/2
y = -2 <=== here it is
Let the distance of the first part of the race be x, and that of the second part, 15 - x, then
x/8 + (15 - x)/20 = 1.125
5x + 2(15 - x) = 40 x 1.125
5x + 30 - 2x = 45
3x = 45 - 30 = 15
x = 15/3 = 5
Therefore, the distance of the first part of the race is 5 miles and the time is 5/8 = 0.625 hours or 37.5 minutes
The distance of the second part of the race is 15 - 5 = 10 miles and the time is 1.125 - 0.625 = 0.5 hours or 30 minutes.
