Question

7
solve the system of equations by substitution
$y = x - 1$
$x + 4y = 16$

Explanation:

Step1: Substitute $y=x-1$ into the second equation

$x + 4(x - 1) = 16$

Step2: Expand and simplify the equation

$x + 4x - 4 = 16$
$5x - 4 = 16$

Step3: Solve for $x$

$5x = 16 + 4$
$5x = 20$
$x = \frac{20}{5} = 4$

Step4: Substitute $x=4$ into $y=x-1$

$y = 4 - 1 = 3$

Answer:

$x=4$, $y=3$