Find the intercepts by making x and y zero and solving for the other variable.
Q23 y = 4 + 2x. When x = 0 then y = 4 + 2x0 = 4. When y = 0 then 4 + 2x = 0 so x = -2
Plot the points (0, 4) and (-2, 0) and use a ruler to draw a line through them.
Q26 Use the points (0, 4) and (4, 0)
Q27 Use the points (0, 3) and (-3, 0)
Your flash has hidden part of the other questions but you could rearrange into the form y = mx + c or simply find two points that match the rule.
Q29 is different. It is a vertical line through -2 on the x-axis so it passes through (-2, 0) (-2, 2) (-2, 10) etc