Question

solve the system of equations using the substitution method.\

$$\begin{cases}4x + 5y = 7\\\\y = 3x + 9\\end{cases}$$

\
enter your answers in the boxes.\
x = \square\
y = \square

Explanation:

Step1: Substitute $y=3x+9$ into first equation

$4x + 5(3x + 9) = 7$

Step2: Expand and simplify the equation

$4x + 15x + 45 = 7$
$19x + 45 = 7$

Step3: Solve for $x$

$19x = 7 - 45$
$19x = -38$
$x = \frac{-38}{19} = -2$

Step4: Substitute $x=-2$ into $y=3x+9$

$y = 3(-2) + 9$

Step5: Calculate the value of $y$

$y = -6 + 9 = 3$

Answer:

$x = -2$
$y = 3$