Use algebra in context
Interactive practice questions
Sarah decides to put a bird feeder in her back garden. That day she sees $6$6 birds use the feeder. The next day she sees $12$12 birds, and on the third day she sees $18$18 birds.
If the number of birds continues to follow the pattern, how many birds will Sarah see on the fourth day?
If the pattern continues, write an expression for the number of birds Sarah will see after $y$y days.
A tap has not been turned off properly, and water is dripping into the bucket underneath it. After one hour, the water level in the bucket is $6$6 cm. After two hours the water level is at $12$12 cm, and after three hours the water level reaches $18$18 cm.
Tom likes to go kayaking, and on Saturday he takes his boat down to the lake which is $350$350 m away from his house. After one minute of paddling he is $420$420 m away from his house. After two minutes he is $490$490 m away, and after three minutes he reaches $560$560 m away.
An isosceles triangle has two sides of length $6$6 cm.
If the third side has a length of $b$b cm, write an expression for the perimeter of the triangle.