First, we divide 54 by 4.5 to find out how many miles she can ride in 1 hour, then multiply that to 6 to find how many miles she can ride in 6 hours. 54 / 4.5 = 12, and 12 x 6 = 72, so she can ride 72 miles in 6 hours. :)
First, let's put the second equation, <span>x-2.23y+10.34=0, in terms of y:
x - 2.23y +10.34 = 0
2.23y = x + 10.34
y = .45x + 4.64
Now we can substitute the right side of this equation for y in the first equation
</span><span>y=2x^2+8x
.45x + 4.64 = 2x^2 + 8x
Turn it into a quadratic by getting 0 on one side:
2x^2 + 8x - .45x - 4.64 = 0
2x^2 + 7.55x - 4.64 = 0 Divide both sides by 2
x^2 + 3.76x - 2.32 = 0
x =( -b +/- </span>√(b² - 4ac) ) / 2a
x =( -3.76 +/- √(14.14 + 9.28)) ÷ 2
x = .54 or -4.31
Plug the x values into y = .45x + 4.64
y = .45 (.54) + 4.64
y = 4.88 when x= .54
y = .45 (-4.31) + 4.64
y = 2.70 when x= -4.31
Solution set:
{ (0.54, 4.88) , (-4.31, 2.70) }
Answer:
0.4
Step-by-step explanation:
Answer:
65 mph on level road
Step-by-step explanation:
Set b as average speed on the level road and (b-20) = average speed on the winding road
Distance = speed * time
Level Road distance + winding road dististance = 285 miles
Substituting b and (b-20), we have,
3b + 2(b-20) = 285
3b + 2b - 40 = 285
5b = 285 + 40
5b = 325
b= 325/5
b = 65 mph on level road
