Answer:
10 hours
Step-by-step explanation:
(150/x) + 1.5 + (450/(x+15)) = 600/x
Multiply through by x(x + 15):
150(x + 15) + 1.5x(x + 15) + 450x = 600(x + 15)
150x + 2250 + 1.5x^2 + 22.5x + 450x = 600x + 9000
150x + 2250 + 1.5x^2 + 22.5x + 450x - 600x - 9000 = 0
1.5x^2 + 22.5x - 6750 = 0
x = (-22.5 +/- sqrt(22.5^2 - 4(1.5)(-6750))) / (2*1.5)
x = (-22.5 +/- sqrt(506.25 + 40500)) / 3
x = (-22.5 +/- sqrt(41006.25)) / 3
x = (-22.5 +/- 202.5) / 3
x = 180/3 or -225/3
x = 60 or -75
But a negative number doesn't make sense, so therefore x = 60, so the journey took 600/60 = 10 hours.
X ·2 = 12x - 15
2x = 12x - 15
2x + (-12x) = (12x - 15) + (-12x)
Result: x = 3/2
What ???? How are we supposed to understand tht
Width= 8 cm
Because 192 / 2 = 96 / 12 = 8
SA= (perimeter * height) + 2 (length * width)
SA= (20*12)+2(2*8)
SA= 240+32
SA= 272 cm2
