The function is given by the formula y = 5x-21. Determine: a) the value of y, if x = -2.5 b) the value of x, at which y = -31

| September 3, 2021 | education

The function is given by the formula y = 5x-21. Determine: a) the value of y, if x = -2.5 b) the value of x, at which y = -31 c) whether the graph of the function passes through the point E (5; 3).

1) Let’s calculate what is the value of y in the function given by the formula y = 5x – 21, if x = -2.5.

5 * – 2.5 – 21 = – 12.5 – 21 = -33.5.

2) Let’s calculate what is the value of x in the function given by the formula y = 5x – 21, if y = -31.

5x – 21 = -31;

5x = -31 + 21;

5x = – 10;

x = -10 / 5;

x = -2.

3) Let’s calculate whether the point E (5; 3) belongs to the graph of the function given by the formula y = 5x – 21. To do this, substitute the value of the argument x = 5 and the value of the function y = 3. If we get the correct equality, then the point belongs.

5 * 5 – 21 = 25 – 21 = 4.

4 is not equal to 3.

Answer: does not belong.



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