In a direct variation, the constant of proportionality is -3.

which of the following would be its equation?

y = x - 3
-3y = x
y = -3x
-3 = xy

The equation is .

Step-by-step explanation:

When we say that a variable varies directly as another variable, or is directly proportionate to another variable, we mean that the variable changes with the same ratio as the other variable increases.

This kind of correlation can be represented as a linear function that passes through the origin, the equation of which is of the form . The two variables we are considering are x and y, while k is called the constant of proportionality.

We know the constant of proportionality k = -3, applying the above definition we get that the equation is .

hello :

by applying the distributive property :

6 × 4.3 = 6 × ( 4 + 0.3 )

            =   (6 ×   4) + (6 ×   0.3)

            = 24 + 1.8

6 × 4.3 = 25.8

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.