Answer:
Step-by-step explanation:
let the speed of one plane=x
speed of other plane=x+80
time=4 hrs
then 4x+4(x+80)=3800
4x+4x+320=3800
8x=3800-320
or 8x=3480
x=435
speed of one plane=435 m/h
speed of other plane=435+80=515 m/h
2.
Let he walks x hrs
then he take a taxi for 2-x hrs
4x+(2-x)50=31
4x+100-50x=31
-46x=-69

so he walks 3/2 hrs=1.5 hrs
travels by taxi=2-1.5=0.5 hrs
distance traveled by taxi=0.5×50=25 miles
Answer:
C
Step-by-step explanation:
x=60
60
60+30=90
60-30=30
60+90+30=180
Each girl will get 4 tangerines
Answer:
Y = 60 degrees and X = 12
Step-by-step explanation:
x+3 and 15 are congruent so x+3 = 15, 12+3 = 15 therefore x = 12
y = 60 vertically opposite angles are equal. :D
Answer:
2%
Step-by-step explanation:
Let x be the first number
It increases by 70 %
The new number is
m = x+ .70x
= 1.7x
Let y be the second number
It decreases by 40 %
The new number is
n =y - .40 y
= .6y
The product of the original numbers is xy
The product of the new number is
mn = (1.7x * .6y) = 1.02xy
The new number is larger than the old number so it is an increase.
Percent increase is new - original divided by original times 100%
Percent increase = (1.02 xy - xy)
----------------- * 100%
xy
= .02 xy
------- * 100 %
xy
= .02 * 100 %
= 2%