The function is given by the formula y = -7x answer the following questions (1-3)

The function is given by the formula y = -7x answer the following questions (1-3) 1What is the value of the function at x = -4? At what value of y is 2.8? Do points A (-3; -21) and C (5; -35) belong to the schedule?

Solution:

1) If x = – 4, then y = – 7 x = – 7 * (- 4) = 28.

2) If y = 2.8, then we get a linear equation with one variable:

2.8 = – 7 * x,

x = 2.8: (- 7),

x = – 0.4.

3) Substitute the abscissa of point A (- 3; – 21) into this equation. We get:

y = -7 * (- 3) = 21, therefore point A (- 3; – 21) does not belong to the graph of the function.

Substitute the abscissa of point C (5; – 35) into this equation. We get:

y = -7 * 5 = – 35, hence the point C (5; – 35) belongs to the graph of the function.