Question

the value of y is directly proportional to the value of x .If y = 124 when x = 8 , what is the value of y when x= - 1/2

Answer 1

-7.75

Explanation:

`\text{if}\ x = 8 \rightarrow y = 124\\y \propto x\\y = kx\\\\124 = k * 8 = 8k\\(124)/(8) = (8k)/(8)\\15.5 = k\\\\\text{We've now found the formula}\\y \propto x\\y = kx = 15.5x\\\\x = -(1)/(2) \rightarrow y = ?\\y = 15.5x = 15.5 * -(1)/(2) = -7.75`