Question

3|-y|+7|4+x| при x=-7=-1

Answer 1

По-моему, такте уравнения решаются так

Answer 2

To evaluate the expression 3|-y|+7|4+x| when x=-7 and x=-1, we need to substitute these values for x and then simplify the expression. However, we cannot evaluate |-y| without knowing the value of y. Therefore, we will evaluate the expression for both values of x and leave it in terms of y.

When x=-7, we have:

3|-y| + 7|4 + x| = 3|-y| + 7|4 - 7| (substituting x=-7) = 3|-y| + 7|-3| = 3|-y| + 21 (since |-3|=3) = 3|y| + 21 (since |-y|=|y|)

So, the expression 3|-y|+7|4+x| when x=-7 is equal to 3|y|+21.

When x=-1, we have:

3|-y| + 7|4 + x| = 3|-y| + 7|4 - 1| (substituting x=-1) = 3|-y| + 7|3| = 3|-y| + 21 (since |3|=3) = 3|y| + 21 (since |-y|=|y|)

So, the expression 3|-y|+7|4+x| when x=-1 is also equal to 3|y|+21.

Therefore, regardless of the value of x, the expression 3|-y|+7|4+x| simplifies to 3|y|+21.