Answer:
x = 49
Explanation:
Given the mathematical expression and data;
y = 1/√x
y = 7 and x = 64
First of all, we would find the constant of proportionality, k;
y = k/√x
7 = k/√64
7 = k/8
k = 7 * 8
k = 56
Next, to find the value of x, when y = 8
y = k/√x
Substituting the values, we have;
8 = 56/√x
Cross-multiplying, we have;
8 * √x = 56
√x = 56/8
√x = 7
Taking the square of both sides, we have;
(√x)² = 7²
x = 49