Algebra 1: Common Core (15th Edition)

$x = 1$ $y = 7$
To solve a system of equations using substitution, we plug in an expression in place of a variable. $6x + 1 = 2x + 5$ Subtract $1$ from each side of the equation to move constants to the right side of the equation: $6x = 2x + 4$ Subtract $2x$ from each side of the equation to move variables to the left side of the equation: $4x = 4$ Divide each side of the equation by $4$ to solve for $x$: $x = 1$ Now that we have the value for $x$, we can substitute it into one of the equations to solve for $y$: $y = 2(1) + 5$ Multiply first: $y = 2 + 5$ Add to solve: $y = 7$