Respuesta :

Esther

Answer:

Caleb and Devon each bowled for [tex]10[/tex] hours and spent [tex]\$55[/tex].

Step-by-step explanation:

Equations:

  • Caleb: y = 4x + 15
  • Devon: y = 5x + 5

Where:

  • x = hours spent bowling
  • y = the total cost

System of equations:

[tex]\begin{cases}y=4x+15\\y=5x+5\end{cases}[/tex]

Solve for x

Step 1: Substitute the second equation into the first.

[tex]\implies 4x+15=5x+5[/tex]

Step 2: Subtract [tex]5x[/tex] from both sides

[tex]\implies 4x-5x+15=5x-5x+5[/tex]

[tex]\implies -x+15=5[/tex]

Step 3: Subtract [tex]15[/tex] from both sides.

[tex]\implies -x+15-15=5-15[/tex]

[tex]\implies -1x=-10[/tex]

Step 4: Divide both sides by [tex]-1[/tex] .

[tex]\implies \dfrac{-1x}{-1}=\dfrac{-10}{-1}[/tex]

[tex]\implies \boxed{x=10}[/tex]

Solve for y

Step 1: Substitute the found [tex]x[/tex] value into one of the system of equations.

[tex]\implies y=4(10)+15[/tex]

Step 2: Multiply and add.

[tex]\implies y=40+15[/tex]

[tex]\implies \boxed{y=55}[/tex]

Therefore, Caleb and Devon each bowled for 10 hours and spent $55.