Answer:
2x + 4
Step-by-step explanation:
Let R = Ralph's age
and x = Sarah's age
Then Ralph's age in 4 years = R + 4
and Sarah's age in four years = x + 4
Thus, R + 4 = 2(x + 4)
Distribute the 2 R + 4 = 2x + 8
Subtract 4 from each side R = 2x + 4
Ralph's age is 2x + 4.
Answer:
x=-14/3
Step-by-step explanation:
3x+5=-9
3x=-9-5
3x=-14
x=-14/3
Answer:
225 + 63n for n- a natural number,
set 512=225+63n to find total number of weeks
63=21*3
use n=4 to solve the amount saved in 4 weeks
they wont 60*4=240, 240+12, 252+225=477
how much are the saving a day
what do they need to put up to have enough in 4 weeks
how much a day do the need to save to go in 1 week
etc
Step-by-step explanation:
Answer:
They will be 170 miles apart at 10 AM
Step-by-step explanation:
Nancy has 15´ of head start which is 1/4 hr.
NHD = 20*(1/4) = 5 miles is her head start
Mark leaves at 7.15hs = starting point
Marks stop at when they are 170 miles apart = t
------------------------------
t = the time they are 170 miles apart
d= distance in miles Nancy travels in time t
170 - (d+5) = distance in miles Mark travels in time t
------------------------------
Nancy's equation:
(1) d = 20t
Mark's equation:
(2) 170 - (d+5) = 40t
---------------------------
(2) 170-d-5=40t
(2) d+40t=165
Substitute (1) into (2)
(2) 20t+40t=165
(2) 60t=165
(2) t=2.75
7:15 AM + 2.75 hrs (2:45hs) = 10 AM
They are 170 miles apart at 10 AM
check:
(1) d=20t
(1) d=20*2.75
(1) d=
55
---------------
(2) 170 - (d+5) = 40t
(2) 170 - (d+5) = 40*2.75
(2) 170 - d-5 = 110
(2) d=55
Answer:
x=17
Step-by-step explanation:
