15 points line ab←→ passes through the points a(3,−1) and b(1,7). which lines are parallel to ab←→? this is multiple choices y=−4x y=−4x+8 y=4x y−1=2(x+2) y+1=−4(x+1) y=4x+7 y=2x−3 y−6=−4(x−3)

Lines that are parrellell presume to have the same slope.

So if we just calculate the slope of a function or a line we should be good.

Now put in the data from the coordinates of the points

The form of a function now looks like:

From here we are no longer required to calculate anything more. Leave n alone.

The solutions are the equations of the form above.

That would mean:

Hope this helps.

exactly you go it

step-by-step explanation:

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240