Chapter F - Foundations: A Prelude to Functions - Section F.2 Graphs of Equations in Two Variables; Intercepts; Symmetry - F.2 Assess Your Understanding - Page 16: 1

$x=-6$

Expand the terms in the parenthesis. $2x+6-1=-7$ Move all unknowns to one side of the equation and all constants to the other. $2x+5=-7$ $2x=-7-5$ $2x=-12$ Solve for $x$ by dividing all terms by $2$. $2x\div2=-12\div2$ $x=-6$