Direct variation y = kx and inverse variation xy = k
Grade 9 Math Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
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Input–output table
x y 4 12 First find k.
Zee knows y varies directly with x, and y = 12 when x = 4. What is the rule, in the form y = kx?
Zee knows y varies inversely with x, and y = 8 when x = 3. What is the rule, in the form y = k/x?
Esme knows y varies inversely with x, and y = 5 when x = 6. What is the rule, in the form y = k/x?
Input–output table
hoses hours 6 10 5 ? Ari's class has 6 hoses filling a pool in 10 hours, all at the same rate. How many hours would 5 hoses need?
Input–output table with two rows
The second row has its input doubled or tripled.
Tala knows y varies directly with x. If x doubles, what happens to y?
- y doubles
- y is halved
- y goes up by 2
Jun knows y varies inversely with x. If x doubles, what happens to y?
- y doubles
- y is halved
- y goes down by 2
Pia knows y varies inversely with x. If x triples, what happens to y?
- y is multiplied by 3
- y goes down by 3
- y is divided by 3
Input–output table
x y 6 4 15 ? The constant k is not a whole number.
Bo knows y varies directly with x, and y = 4 when x = 6. What is y when x = 15?
Milo knows y varies directly with x, and y = 6 when x = 8. What is y when x = 20?
Zee knows y varies directly with x, and y = 6 when x = 9. What is y when x = 21?