I need help for a project! What would the variables be defined as!?
Marvin burned 8 calories per minute on a treadmill and 10 calories
per minute on an elliptical trainer for a total of 560 calories in 60
minutes. Write and solve a system of linear equations to determine
how many minutes he spent on each machine.

2  1/5x * 1 7/10 y  *  4  3/5 x 1 7/10  (* 7 4/50)

Finds the answer  

10 6/50x  *  7  41/50y   (* 7/4/50)  = 56

79 13/100  (* 7 4/50)  = 56

560  = 56 (10x)

x = 5 6/10

7 (y) = 56 (7y)

8 = 56/7  (y)

y = 8

x = 5 6/10

6/10 of 560  = 336  

336/60 = x

336/60 = 5 6/10

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct