Question

PLEASE HELP! URGENT!

1: Write an equation of the line that passes through the points (−2,−7) and (0,−4).
2:Write an equation of a line that passes through the point (2,1) and is perpendicular to the line y=13x+2.
3:You have an initial amount of $55 in a savings account and you deposit an equal amount into your account each week. After 6 weeks the account holds $133. Write an equation that represents the amount y (in dollars) of money in the account after x weeks.

Answer 1

1: y=(3x/2)-4 2 :y=(-x/13)+(15/13) 3: y = 13x+55

Explanation:

1:

Begin by finding slope

m = (y2-1)/(x2-1)

(-7-(-4)/(-2-0) = 3/2

next use point slope form

y-y1 = m(x-x1) (you can pick any point to use, I will use (0,-4)

y-(-4) = 3/2(x-0)

y+4 = 3x/2

y=(3x/2)-4

2:

The slope of the line y=13x+2 is 13

Take the opposite sign and reciprocal of 13 to get the slope of the line perpendicular; in this case it's -1/13

Next, just like in problem 1, use point slope form.

y-1 = (-1/13)(x-2)

y-1 = (-x/13)+(2/13) (convert 1 to 13/13 for like terms and bring over to the left side)

y=(-x/13)+(15/13)

3:

the intercept will be $55 since it's the initial amount

you know that you deposit some amount every week so set this up as an equation

$133 = m(6)+$55 (the amount deposited every week times 6 +the initial $55 will equal $133)

solving for m gets you $13

so the equation is y = 13x+55

plug in 6 for x to check; 13x6 + 55 = 133

hope this helps