15 mi/h= 15mi/60 min= 1/4 (mi/min)
x is original speed (mi/min)
t is original time
x*t =260
(x+1/4)=5x/4 is new speed
t-20 - new time
(x+1/4)(t-20)=260
xt = (x+1/4)(t-20)
xt=xt + t/4 - 20x - 5
t/4=20x+5
t=80x +20
We can substitute t=80x +20 into equation x*t =260
x*(80x+20)=260
80x²+20x-260=0
4x²+x-13=0
D=b² - 4ac = 1+4*4*13= 209
x=(-1+/-√209)/2*4
x=1.68 mi/min
1.68mi/min * 60 min/1h≈100 mi/h
Check
260/100=2.6h time with old speed
260/(115)=2.26 h time with new speed
2.6-2.26 = 0.34 h difference between old and new time
0.34h*60min/1h≈20 min difference between old and new time in minutes
Answer:
x = 2+1/3i or 2-1/3i
Step-by-step explanation:
The equation of interest can be written in vertex form as ...
9(x -2)² +1 = 0
so its solutions can be found by subtracting 1, dividing by 9, taking the square root, then adding 2.
x = 2 ± √(-1/9)
In the desired form, the zeros of the given expression are ...
x = 2 +1/3i or 2 -1/3i
Answer:
0.75
Step-by-step explanation:
i did it and got the wrong answers and it said the right answer is 0.75
Answer:
78.54 m
Step-by-step explanation:
To obtain how much circular fence, we obtain the Circumference of the circular playground.
The Circumference of a circle, C = 2*pi*r
pi = 3.14 ; r = diameter / 2 = 25 /2 = 12.5 m
C = 2 * 3.14 * 12.5
C = 78.539816
Hence, the fencing which need to go up is ;
78.54 m
