Let's solve the system of equations step by step:
The given system is:
$$ \begin{cases} 2y + 2x = 69.48 \\ y + 12.8 = x \end{cases} $$Step 1: Substitute the value of x from the second equation into the first equation.
From the second equation, we have ( x = y + 12.8 ). Substitute this into the first equation:
$$ 2y + 2(y + 12.8) = 69.48 $$Step 2: Simplify and solve for y.
Expand and simplify the equation:
$$ 2y + 2y + 25.6 = 69.48 $$ $$ 4y + 25.6 = 69.48 $$Subtract 25.6 from both sides:
$$ 4y = 69.48 - 25.6 $$ $$ 4y = 43.88 $$Divide by 4 to find the value of y:
$$ y = \frac{43.88}{4} $$ $$ y = 10.97 $$Step 3: Substitute the value of y back into the second equation to find x.
We have ( x = y + 12.8 ), and now we know ( y = 10.97 ), so:
$$ x = 10.97 + 12.8 $$ $$ x = 23.77 $$Step 4: Write the final answer.
The solution to the system of equations is ( x = 23.77 ) and ( y = 10.97 ).
Answer: x = 23.77, y = 10.97