Sam makes $400 per week plus $20 commission on each new sell phone plan he sells. write an equation to determine how many new plans she sold to earn $680 last week

She sold 14 new plans to earn $680 last week.

Step-by-step explanation:

$400 + 20(x) = $680

Take 400 away from total cost. So, 680 - 400 = 280.

Now, divide 280 by 20, and x = 14.

The equation would be $400 + 20(14) = $680

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