Samir is a roofer. Here is a section of a roof made from straight pieces of wood.

Samir knows that

• the shaded triangle is an equilateral triangle

• the line DB is a line of symmetry

• the line ABC is a straight line

• the size of the angle marked x° indicates the pitch of the roof.

The table shows information about the pitch and angle of a roof.

Find the value of x and use the table to give the pitch of the roof.

Look at this system of equations. -3x + 3y = 12 y = x + 4 the solution set of this system is best explained by which of these statements? a) the graphs of the equations are the same line because the equations have the same slope and the same y-intercept. the system has infinitely many solutions. b) the graphs of the equations are parallel lines because they have the same slope but different y-intercepts. the system has no solution. c) the graphs of the equations are lines that intersect at one point because the equations have the same slope but different y-intercepts. the system has exactly one solution. d) the graphs of the equations are lines that intersect at one point because the equations have the same slope and the same y-intercept. the system has exactly one solution.