Answer:
Iance burned 15 calories per minute running and 8 calories per minute swimming
Step-by-step explanation:
Let
x = number of calories burned per minute running
y = number of calories burned per minute swimming
On Monday
ran 30 min - burned 30x calories
swam 20 min - burned 20y calories
In total, [tex]30x+20y=610[/tex] calories.
On Wednesday
ran 25 min - burned 25x calories
swam 40 min - burned 40y calories
In total, [tex]25x+40y=695[/tex]
You get the system of two equations:
[tex]\left\{\begin{array}{l}30x+20y=610\\ \\25x+40y=695\end{array}\right.\Rightarrow \left\{\begin{array}{l}3x+2y=61\\ \\5x+8y=139\end{array}\right.[/tex]
Multiply the first equation by 4 and subtract the second equation from the first:
[tex]4(3x+2y)-(5x+8y)=4\cdot 61-139\\ \\12x+8y-5x-8y=244-139\\ \\7x=105\\ \\x=15[/tex]
Substitute it into the first equation:
[tex]3\cdot 15+2y=61\\ \\45+2y=61\\ \\2y=61-45\\ \\2y=16\\ \\y=8[/tex]
Iance burned 15 calories per minute running and 8 calories per minute swimming
