AlgebraMediumMissing coordinate on a line
Algebra practice question
The line 3x − 4y = 10 passes through the point (−2, k). What is the value of k?
Answer: -4 or −4
Substitute x = −2: −6 − 4k = 10, so −4k = 16 and k = −4.
Common wrong answers
- If you answered 1
- 1 comes from −6 + 4k = 10 (sign slip on the 4y term).
- If you answered 4
- 4 has the wrong sign; −6 − 4k = 10 gives −4k = 16.
- If you answered -1
- −1 solves 3x − 4y = 10 for x = 2, not x = −2.
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