Respuesta :
Answer:
- 4 hours
Step-by-step explanation:
Use a couple of ordered pairs on the graph and get the equation of the line:
- (0, 2), (1, 10)
The y-intercept is 2 and the slope is 10 - 2 = 8
The line is
- y = 8x + 2
Solve the system of equations by substitution to find the intersection
- y = 6x + 10
- y = 8x + 2
- 6x + 10 = 8x + 2
- 8x - 6x = 10 - 2
- 2x = 8
- x = 4
They will work 4 hours to get same amount of saving
Answer:
4 hours
Step-by-step explanation:
First, create a linear equation for Carlos using the graph.
Two points on the line: (0, 2) and (1, 10)
[tex]\implies \sf slope\:(m)=\dfrac{change\:in\:y}{change\:in\:x}=\dfrac{10-2}{1-0}=8[/tex]
Use the point-slope equation with the found slope and one of the points:
[tex]\implies y-y_1=m(x-x_1)[/tex]
[tex]\implies y-2=8(x-0)[/tex]
[tex]\implies y=8x+2[/tex]
Now equate the equations for Mary Ann and Carlos, and solve for x:
[tex]\implies 6x+10=8x+2[/tex]
[tex]\implies 8=2x[/tex]
[tex]\implies x=4[/tex]
Therefore, Mary Ann and Carlos have saved the same amount after 4 hours work.