Answer:
36
Step-by-step explanation:
-9*-4=36
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:
only one has the value of -12
Step-by-step explanation:
like what
The area of figure ABCDEF can be computed as the sum of the areas of trapezoid ACDF and triangle ABC, less the area of trangle DEF.
trapezoid ACDF area = (1/2)(AC +DF)·(CD) = (1/2)(8+5)(6) = 39
triangle ABC area = (1/2)(AC)(2) = 8
triangle DEF area = (1/2)(DF)(2) = 5
Area of ABCDEF = (ACDF area) + (ABC area) - (DEF area) = 39 +8 -5 = 42
The actual area of ABCDEF is 42 square units.
Answer:
yes I am the only one that has a lil before I go to