In 1 hour, Antoine travels 1.75 mi by dividing 5.25 by 3. So, after lunch, he hiked 4 hours. 1.75 times 2 is 3.5 mi every hour after lunch. So, 3.5 times 4 is 14 mi. + 5.25 is 19.25 mi., or 19 1/4 miles.
a+b+c=0
[(a+b+c)^2=a^2+b^2+c^2+2ab+2ac+2bc]
[a^2+b^2+c^2+2ab+2ac+2bc=0]
[a^2+b^2+c^2=-(2ab+2ac+2bc)]
[a^2+b^2+c^2=-2(ab+ac+bc)] (i)
also
[a=-b-c]
[a^2=-ab-ac] (ii)
[-c=a+b]
[-bc=ab+b^2] (iii)
adding (ii) and (iii) ,we have
[a^2-bc=b^2-ac] (iv)
devide (i) by (iv)
[(a^2+b^2+c^2)/(a^2-bc)=(-2(ab+bc+ca))/(b^2-ac)]
<em><u>45(x)-20 </u></em>
x=hours
7 hours
x=7
<em><u>45(7)-20 =295</u></em>
3x + 6 = 12
First operation was subtraction (subtracting 6 to leave 3x alone)
Second operation was division (Dividing 3 from 3x to isolare x)
3x + 6 = 12
3x + 6 -(6) = 12 - 6
3x = 6

=

3 and 3 cancels out
x = 2