Respuesta :
We know that Luke lost x pounds the first week.
We also know that the second week 3/2 less than 3/2 times the pounds he lost the first week, this means that the secons week he lost:
[tex]\frac{3}{2}x-\frac{3}{2}[/tex]Finally the third week he lost 1 pound more than 3/4 of the pounds he lost the first week. This can be written as:
[tex]\frac{3}{4}x+1[/tex]Hence luke lost a total of:
[tex]x+\frac{3}{2}x-\frac{3}{2}+\frac{3}{4}x+1=\frac{13}{4}x-\frac{1}{2}[/tex]Therefore the expression for Luke's weight loss is:
[tex]\frac{13}{4}x-\frac{1}{2}[/tex]Liam lost the first week 1 pound less than 3/2 times the loss Luke had the first week this can be express as:
[tex]\frac{3}{2}x-1[/tex]The second week he lost 4 pounds less than 5/2 times the loss of Luke the firs week then we have:
[tex]\frac{5}{2}x-4[/tex]Finally Liam lost 1/2 pound more than 5/4 times the loss of Luke the first week, then:
[tex]\frac{5}{4}x+\frac{1}{2}[/tex]Adding this we have:
[tex]\frac{3}{2}x-1+\frac{5}{2}x-4+\frac{5}{4}x+\frac{1}{2}=\frac{21}{4}x-\frac{9}{2}[/tex]Therefore Liam's expression is:
[tex]\frac{21}{4}x-\frac{9}{2}[/tex]Now, we know that both of them lost the same weight, then we have the equation:
[tex]\frac{13}{4}x-\frac{1}{2}=\frac{21}{4}x-\frac{9}{2}[/tex]Solving for x we have:
[tex]\begin{gathered} \frac{13}{4}x-\frac{1}{2}=\frac{21}{4}x-\frac{9}{2} \\ \frac{21}{4}x-\frac{13}{4}x=\frac{9}{2}-\frac{1}{2} \\ \frac{8}{4}x=4 \\ x=\frac{4}{\frac{8}{4}} \\ x=2 \end{gathered}[/tex]Therefore Luke lost 2 pound the first week.
Finally we plug the value of x in the expression for Luke's weight loss to get the total amount over the three weeks:
[tex]\begin{gathered} \frac{13}{4}(2)-\frac{1}{2}=\frac{13}{2}-\frac{1}{2} \\ =\frac{12}{2} \\ =6 \end{gathered}[/tex]Therefore they lost 6 pounds in three weeks.
