3.
We know that Hobby Land sells art supplies two different ways.
We can represent the situation with a system of equations
[tex]\begin{cases}x+y=139\ldots(1) \\ 4x+7y=781\ldots(2)\end{cases}[/tex]
Where x is the cost of one easel and y represents the cost of one paint set.
Now, we must solve the system of equations.
We can multiply equation (1) by -4
[tex]\begin{gathered} -4(x+y)=-4(139) \\ -4x-4y=-556\ldots(3) \end{gathered}[/tex]
Then, we can add (3) + (2)
[tex]\begin{gathered} -4x-4y=-556 \\ 4x+7y=781 \\ -------------- \\ 3y=225 \end{gathered}[/tex]
Now, we can solve the equation for y
[tex]\begin{gathered} 3y=225 \\ y=\frac{225}{3}=75 \end{gathered}[/tex]
Finally, to find x we can replace the value of y in the equation (1)
[tex]\begin{gathered} x+75=139 \\ x=139-75=64 \end{gathered}[/tex]
So, the cost of one easel is $64.
Solution as either an ordered pair:
- (64, 75).
