Sagot :
c=carlos's hour, m=maria
55c+47m=197
c+m=3.8
c=-m+3.8
55(-m+3.8)+47m=197
-55m+209+47m=197
-8m=-12
m=1.5
maria drove 1.5hr or 1 and a half hr.
55c+47m=197
c+m=3.8
c=-m+3.8
55(-m+3.8)+47m=197
-55m+209+47m=197
-8m=-12
m=1.5
maria drove 1.5hr or 1 and a half hr.
Hello !
Maria : x [tex]55y+47x=197 \\ x+y=3.8 \\ y=3.8-x[/tex]
Carlos : y
[tex]55(-x+3.8)+47x=197 \\ -55x+209+47x=197 \\ 209-197=55x-47x \\ 12=8x \\12/8=x \\ 1.5=x \\ \\ Maria drove 1.5 hour or 1 hour 30 minute. [/tex]
Maria : x [tex]55y+47x=197 \\ x+y=3.8 \\ y=3.8-x[/tex]
Carlos : y
[tex]55(-x+3.8)+47x=197 \\ -55x+209+47x=197 \\ 209-197=55x-47x \\ 12=8x \\12/8=x \\ 1.5=x \\ \\ Maria drove 1.5 hour or 1 hour 30 minute. [/tex]