Answer:
A. f(x)=x^2+x+0.25
Step-by-step explanation:
If x represents Lindsey's distance at 2:00 PM, then 2x represents Kara's distance at 2:00 PM because she walked twice as far as Lindsey. Then adding on the values we got for 2:30 PM, we get that Kara walked a distance of 2x+1 and Lindsey walked a distance of x+0.5 at the time of 2:30 PM. Now, we know that they have formed a right triangle because we are given the directions they walked in; east and north. This allows us to use a formula for the area of a right triangle: 1/2(L x W). Plugging in our values, we get...
1/2(2x+1)(x+0.5)
which simplifies to...
1/2(2x^2+2x+0.5)
which further simplifies to...
x^2+x+0.25
which is our answer.
Answer:

Step-by-step explanation:
Given:

Required
Rewrite in vertex form
The vertex form of an equation is in form of: 
Solving: 
Subtract 2 from both sides


Factorize expression on the right hand side by dividing through by the coefficient of x²


Get a perfect square of coefficient of x; then add to both sides
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<em>Rough work</em>
The coefficient of x is 
It's square is 
Adding inside the bracket of
to give: 
To balance the equation, the same expression must be added to the other side of the equation;
Equivalent expression is: 
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The expression becomes



Factorize the expression on the right hand side





Make y the subject of formula

<em>Solved</em>
To find the unit rate, divide total miles by number of gallons:
418 miles / 16 gallons = 26.125 miles per gallon
Round the answer as needed.
Answer:
last year 100 boys and 60 girls, for a total of 160.
this year, 120 boys and 75 girls, for a total of 195.
35 more than 160 is a 21.8% increase