1 A rectangular picture frame has perimeter 70 cm.
a The width of the frame is x cm. Find an
expression, in terms of x, for the height
of the frame.
b Find an equation for the area of the
frame, Acm?, in terms of x.
c Plot the graph which shows how A
varies with x. Use a suitable domain and
range. Hence sketch the graph on paper.
d Find the x-intercepts of the graph in part c.
e State what these two values of x represent.
f Hence find the equation of the graph's
line of symmetry, and state what this
tells you in the context of the problem.

you answer is a

step-by-step explanation:

i think it is c, not positive though

step-by-step explanation:

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."