Answer:
200
Step-by-step explanation:
Mark me as brainliest
Answer:Recognise three numbers that are related through the operations of addition and subtraction.
Recognise that there are two related addition and two subtraction equations in a 'family of facts'.
Write and read sets of related addition and subtraction equations.
Step-by-step explanation:that is all
The quantity reported an <em>equivalent net</em> percentage change of 28 percent.
<h3>How to calculate the net change of a quantity in percentages</h3>
In this problem we must determine the <em>simple</em> percentage change equivalent to two <em>consecutive</em> percentual changes. The formula that describes the situation is:
1 + r/100 = (1 - 60/100) · (1 + 80/100)
1 + r/100 = 72/100
r/100 = - 28/100
r = - 28
The quantity reported an <em>equivalent net</em> percentage change of 28 percent.
<h3>Remark</h3>
The statement is incomplete. Complete form is presented below:
A quantity is changing. At first it descreased by 60 percent and it increased by 80 percent. What is net change of the quantity in percentage?
To learn more on percentages: brainly.com/question/13450942
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Answer: He actually rode 2 miles per hour on his trip
Step-by-step explanation: Maybe unconventional, but express the time it took, then figure the speed.
Time = distance /speed t will represent time, s is the speed: t = 30/s Use the rime it would have taken at the higher speed to create an equation:
t-12 = 30/s+8 replace the y with the 30/s
30/s -12 = 30/s+8
(s)(30/s -12 ) = (s)(30/s+8 ) Cross multiply to cancel denominators
(s-8)(30 -12s) = (s-8)(30s/s+8 ) ==> 30s +240 -12s² -96s =30s Simplify:
(-1)(-12s² -96s +240 ) =0 ==> 12s² +96s -240 divide all by 12
s² + 8s -20 = 0 Factor and solve for s
(s +10)(s -2) =0 s-2=0 S= 2
Proof:
30/2 = 15 hours for original trip at 2mph,
increase speed by 8mph 2 + 8 = 10mph
30 miles at 10mph takes 3 hours; that is 12 hours less than his actual trip.
(Brainilest, please :-)
