Writing Proportion with Algebra

Select the equation equivalent to

"A is directly proportional to B"

• A = kB

• a = kb

• A = B^k

• A = k^B

Select the equation equivalent to

"x is directly proportional to y"

• x = ky

• X = kY

• X = Y^k

• x = k^y

C is directly proportional to D

Write an equation for C in terms of D

x is directly proportional to y

Write an equation for x in terms of y

In a spring, the tension (T newtons) is directly proportional to the extension of the spring (y cm).

Write an equation for T in terms of y

Which graph shows that y and x are in direct proportion?

• 
• 
• 
• 

Select all the answers below which mean the same thing

• a is directly proportional to b

• $a=kb$

• $a\propto b$

• As a increases, b increases

What type proportional relationship is shown here?

Number of teachers and time taken to mark a set of exam papers

• Direct proportion

• Inverse proportion

What type proportional relationship is shown here?

Weight of dog and amount of dog food needed

• Direct proportion

• Inverse proportion

What type proportional relationship is shown here?

Number of rabbits and time taken to eat a bowl of rabbit food

• Direct proportion

• Inverse proportion