Help me answer please.

see explanation

Step-by-step explanation:

(a)

For the graph to display direct proportion it must pass through the origin.

The graph shown does not pass through the origin thus does not represent direct proportion.

(b)

Given that q is directly proportional to r then the equation relating them is

q = kr ← k is the constant of proportion

To find k use the condition q = 76 when r = 20, thus

76 = 20k ( divide both sides by 20 )

3.8 = k

q = 3.8r ← equation of proportion

When r = 45, then

q = 3.8 × 45 = 171

x = 25

step-by-step explanation:

a^2+b^2=c^2

7^2+24^2=c^2

49+576=625

sqrt625=25

x=25