karissa2392
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Alex burns 10 calories a minute lifting weights and 14 calories a minute running on a treadmill. if he spend an hour on his workout and burned a total of 668 calories how long did he lift weights​

Respuesta :

absor201

Alex lifted weights for 43 minutes.

Step-by-step explanation:

Given,

Calories burned per minute by lifting weight = 10 calories

Calories burned per minute by running on treadmill = 14 calories

1 hour = 60 minutes

Total calories burnt = 668

Let,

Time spent on weightlifting = x

Time spent running on treadmill = y

According to given statement;

x+y=60    Eqn 1

10x+14y=668    Eqn 2

Multiplying Eqn 1 by 10

[tex]10(x+y=60)\\10x+10y=600\ \ \ Eqn\ 3[/tex]

Subtracting Eqn 3 from Eqn 2

[tex](10x+14y)-(10x+10y)=668-600\\10x+14y-10x-10y=68\\4y=68[/tex]

Dividing both sides by 4

[tex]\frac{4y}{4}=\frac{68}{4}\\y=17[/tex]

Putting y=17 in Eqn 1

[tex]x+17=60\\x=60-17\\x=43[/tex]

Alex lifted weights for 43 minutes.

Keywords: linear equation, elimination method

Learn more about elimination method at:

  • brainly.com/question/7128279
  • brainly.com/question/702593

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