Step-by-step explanation:
Select all of the following that are quadratic equations.
x² + 3x - 5 = 0 ✓
x² - x = 3x + 7 ✓
5x - 7 = 0 X
7x² + 14x = 0 ✓
x³ - 3x² + 1 = 0 X
x - 5 = 9x + 7 X
What is quadratic equations?
Quadratic equations is a equation that has a general form like "ax² + bx = c"
For example :
x² + 3x - 5 = 0
x² + 3x = 5
x² → ax²
3x → bx
5 → c
Answer:
5n^2+(4n)-1
Step-by-step explanation:
(5n-1)(n+1)=0
Lets find <em>n.</em>
(5n-1)(n+1)=0
FOIL it.
5n^2+5n-1n-1
Add/Substract similar factors
5n^2+(5n-1n)-1
5n^2+(4n)-1
Thats your answer.
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Answer:
10 hours.
Step-by-step explanation:
Two bicyclists are 200 miles apart when they start racing towards one another.
Their speeds are 12 mph and 6 mph respectively.
Distance = speed × time
Let the time taken by bicyclists = t
We have to calculate the time when they 20 miles apart this means they have covered the distance of 200 - 20 = 180 miles
t(12mph) + t(6mph) = 180
18t = 180
t = 
t = 10 hours
It will take 10 hours to both the bicyclists before they are 20 miles apart.