Leila purchased 21.5 centimeters of wire for $17.20.

Write the equation of the line that passes through (−3,1) and (2,−1) in slope-intercept form

Alex787 [66]

Answer:

$y=-\frac{2}{5}x-\frac{1}{5}$

Step-by-step explanation:

The equation of a line is y = mx + b

Where:

m is the slope

b is the y-intercept

First, let's find what m is, the slope of the line.

Let's call the first point you gave, (-3,1), point #1, so the x and y numbers given will be called x1 and y1.

Also, let's call the second point you gave, (2,-1), point #2, so the x and y numbers here will be called x2 and y2.

Now, just plug the numbers into the formula for m above, like this:

$m = -\frac{2}{5}$

So, we have the first piece to finding the equation of this line, and we can fill it into y=mx+b like this:

$y=-\frac{2}{5}x + b$

Now, what about b, the y-intercept?

To find b, think about what your (x,y) points mean:

(-3,1). When x of the line is -3, y of the line must be 1.
(2,-1). When x of the line is 2, y of the line must be -1.

Now, look at our line's equation so far: $y=-\frac{2}{5}x + b$ . $b$ is what we want, the - $-\frac{2}{5}$ is already set and x and y are just two 'free variables' sitting there. We can plug anything we want in for x and y here, but we want the equation for the line that specfically passes through the two points (-3,1) and (2,-1).

So, why not plug in for x and y from one of our (x,y) points that we know the line passes through? This will allow us to solve for b for the particular line that passes through the two points you gave!

You can use either (x,y) point you want. The answer will be the same:

(-3,1). y = mx + b or $1=-\frac{2}{5} * -3 + b$ , or solving for b: $b = 1-(-\frac{2}{5})(-3)$ . $b = -\frac{1}{5}$ .
(2,-1). y = mx + b or $-1=-\frac{2}{5} * 2 + b$ , or solving for b: $b = 1-(-\frac{2}{5})(2)$ . $b = -\frac{1}{5}$ .

See! In both cases, we got the same value for b. And this completes our problem.

The equation of the line that passes through the points (-3,1) and (2,-1) is $y=-\frac{2}{5}x-\frac{1}{5}$

8 0

3 years ago

St Question 1 Calculate the derivative of y = f(x) = 3 x(4x + 7) Your answer:

kondor19780726 [428]

Answer:

$\frac{dy}{dx} = 24 x + 21$

Step-by-step explanation:

Explanation:-

Given that the function

y = f(x) = 3 x ( 4 x + 7)

y = 3 x ( 4 x + 7)

y = 12 x² + 21 x ..(i)

Differentiating equation (i) with respective to 'x' , we get

$\frac{dy}{dx} = 12 (2x) +21 (1)$

$\frac{dy}{dx} = 24 x + 21$

6 0

2 years ago

Pls help what’s the slope

kramer

Answer:

The slope of this is -3

Step-by-step explanation:

slope = change in y/ change in x or rise/run!!!

you move 3 down and 1 to the right. So basically -3/1 which can be simplified to -3!!!!

3 0

3 years ago

Read 2 more answers

Dividing integers

Natasha2012 [34]

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =11

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =1111. (-40) ➗10=-4

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =1111. (-40) ➗10=-415. 90 ➗ (-15)=-6

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =1111. (-40) ➗10=-415. 90 ➗ (-15)=-616. 108 ➗ (-9)=-12

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =1111. (-40) ➗10=-415. 90 ➗ (-15)=-616. 108 ➗ (-9)=-1217. (-48) ➗ (-6)=8

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =1111. (-40) ➗10=-415. 90 ➗ (-15)=-616. 108 ➗ (-9)=-1217. (-48) ➗ (-6)=818. (-105) ➗ 7=-15

first we shall learn the rules.when numbers with same sign are divided it gives pisitive sign but, when numbers of different signs are divided it gives negetive sign.here,7. (-154) ➗ (-14) =1111. (-40) ➗10=-415. 90 ➗ (-15)=-616. 108 ➗ (-9)=-1217. (-48) ➗ (-6)=818. (-105) ➗ 7=-15hope it helps you...........

8 0

3 years ago

I need to know both answer to the second part

Ierofanga [76]

Answer:

110 chocolate cupcakes

88 vanilla cupcakes

Step-by-step explanation:

5chocolate to 4 vanilla

5x+ 4x = 9x

9x=198,

x = 22

22 * 5=110 chocolate cupcakes

22 * 4=88 vanilla cupcakes

CHECK: 88 + 110 = 198

5 0

3 years ago