When we are given the value of the independent variable, we can use the least-squares regression line to predict the value of the dependent variable.
When we are given the value of the [blank] variable, we can use the least-squares regression line to predict the value of the [blank] variable.
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When we are given the value of the [response or explanatory?] variable, we can use the least-squares regression line to predict the value of the [predictor or outcome?] variable.
When we are given the value of the explanatory variable, we can use the least-squares regression line to predict the value of the response variable.
In this context, the explanatory variable is often referred to as the predictor variable, and the response variable is commonly referred to as the outcome variable. However, the phrasing you chose ("explanatory" and "response") is more aligned with statistical terminology.