Answer:
x^2-x-5
Step-by-step explanation:
1. expand the square
(+1)(+1)−3(+2)
2. distribute
(+1)+1(+1)−3(+2)
3. distribute
^2++1(+1)−3(+2)
4. multiply by 1
^2+++1−3(+2)
5. combine like terms
^2+2+1−3(+2)
6. distribute
^2+2+1−3−6
7. subtract the numbers
^2+2−5−3
8. combine like terms
^2−−5
9. gg you are done
^2−−5
Let
x--------> the time in hours
y-------> the distance in miles
we know that
The speed is equal to

in this problem


<u>Equation First Train</u>

<u>Equation Second Train</u>

---------> equation 
Substitute the values of
and
in the equation 

Solve for x


therefore
<u>the answer is</u>

The answer is A. W (weight) must be LESS than 20 (w<20) and the weight has to be a positive number because the weight of a dog cannot be negative.
I hope this helps! ^-^
Answer:
number 1,2,4
Step-by-step explanation:
these are all equal sides
The answer would be standard deviation.