Dependent and independent variables
Answers are for parents and teachers.
1
A school bus uses 8 litres of fuel on each trip. Write an equation for the fuel f used on t trips and find f for 5 trips.
f = 8t. For t = 5, f = 40 litres. t is independent and f is dependent.
2
Make a table for y = 5x with x = 1, 2, 3, 4, 5.
y = 5, 10, 15, 20, 25.
3
Find the rule: x = 1, 2, 3, 4 gives y = 11, 12, 13, 14.
y = x + 10.
4
The rule is × 9 and the output is 72. Find the input.
72 ÷ 9 = 8.
5
Each hen lays 6 eggs a week. Write an equation for the eggs e laid by h hens, and find e for 7 hens.
e = 6h. For h = 7, e = 42 eggs.