More practice with graphing linear equations.

They are linear functions.

We need only two points to plotting a graph.

5.

y = -x + 6

Choose any two values of x and calculate y.

for x = 0 → y = -0 + 6 = 6 → (0, 6)

for x = 6 → y = -6 + 6 = 0 → (6, 0)

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6.

Convert the equation of line from the standard form to slope-intercept form.

y = mx + b

-15x + 10y = -60      add 15x to both sides

10y = 15x - 60       divide both sides by 10

y = 1.5x - 6

Choose any two values of x and calculate y.

for x = 0 → y = 1.5(0) - 6 = 0 - 6 = -6 → (0, -6)

for x = 4 → y = 1.5(4) - 6 = 6 - 6 = 0 → (4, 0)

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7.

x = -5

It's a vertical line

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8.

15y - 12x = -60      add 12x to both sides

15y = 12x - 60       divide both sides by 15

y = 0.8x - 4

Choose any two values of x and calculate y.

for x = 0 → y = 0.8(0) - 4 = 0 - 4 = -4 → (0, -4)

for x = 5 → y = 0.8(5) - 4 = 4 - 4 = 0 → (5, 0)

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3