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2 years ago

Write the equation of the line that passes through the points (7, -4) and (-1,3), first in point-slope form, and then in

Mathematics

1 answer:

RoseWind [281]2 years ago

5 0

Step-by-step explanation:

first we need to calculate the slope, which is needed in both equation forms.

the slope is the ratio "y coordinate change / x coordinate change" when going from one point on the line to another.

I always prefer to go from left to right (but it works exactly the same way in the opposite direction), so I go from (-1, 3) to (7, -4).

x changes by +8 (from -1 to +7).

y changes by -7 (from +3 to -4).

so, the slope is -7/+8 = -7/8

when (7, -4) is used (I think you have a typo in the problem description up there), the point-slope form is

y - y1 = m(x - x1)

with (x1, y1) being the point coordinates, and m bring the slope

y - -4 = -7/8 × (x - 7)

or simplified

y + 4 = -7/8(x - 7)

the slope-intercept form is

y = mx + n

m being the slope, n being the y-intercept (y value for x=0).

we know already

y = -7/8 x + n

we also use the coordinates of a point here to solve for n :

-4 = -7/8 × 7 + n = -49/8 + n

-32/8 = -49/8 + n

17/8 = n

so, the full equation is

y = -7/8 x + 17/8

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Use always, sometimes or never to make a true statement:

viva [34]

Answer:

1. Intersecting lines are always coplanar

2. Two planes never intersect in exactly one point

3. Three points are always coplanar

4. A plane containing two points of a line always contains the entire line

5. Four points are sometimes coplanar

6. Two lines never meet in more than one point.

7. Two skew lines are never coplanar

8. Line TQ and Line QT are always the same line.

Step-by-step explanation:

Note: Coplanar means "In the same plane"

1. Each line exist in many planes. But different lines must share at least one plane for them to intersect. That is why intersecting lines are always coplanar.

2. Two planes never intersect at exactly one point because only lines intersect at a point. Planes can only intersect along a line.

3.Three points are always coplanar because in geometry, a group of points are coplanar because there is a geometric plane that they all lie on.

4. A plane containing two points of a line always contains the entire line. Yes

5. Four points are only sometimes coplanar because there is a probability that they may all not lie on the same plane

6. Two lines never meet in more than one point because lines are basically straight and cannot bend over to intersect at another point

7. Two skew lines are never coplanar because skews lines are lines that do not intersect and are never parallel.

8. Line TQ and Line QT are always the same line because a line is straight and extends from one point to the other. So, if a line is labelled TQ calling it QT means the same thing

4 0

3 years ago

A square with one side length represented by an expression is shown below

crimeas [40]

It is mentioned in the problem that the shape is a square, hence, we could say that all side's measurement is the same and it is equal. It can be written in a different arrangement of terms, but still, the value to be solved is the same. The sides can be written in the following forms:
S1=6(3X+8)+32+12X
S2=18X+48+32+12X
S3=18X+80+12X
S4=30X+80

3 0

3 years ago

my sister wants to watch 6 star wars movies ,if each movie. is 2 hours , how long will it take her to watch all of the movies?

poizon [28]

12 hours, 6 x 2 = 12.

4 0

3 years ago

Read 2 more answers

shopkeeper purchased a bicycle for rupees 5000 and marked its price a certain percent above the cost price then he sold it at 10

Gennadij [26K]

Lets say the final price of the bike is SP plus 13% VAT. So:

1.13 * SP = 6356.25

SP = 5625

Now SP was after 10% discount on Original Price, say MP. So:

0.9 * MP = 5625

MP = 6250

Therefore, the percent of Marked Price above Cost Price is:

(6250 - 5000) * 100/5000 = 25%

8 0

3 years ago

If sin theta =1/4, theta in quadrant II, find the exact value of cos[theta +pi/6]

Mashcka [7]

Using cos addition formula:
use x for theta
cos(x+π/6)=cosx*cos(π/6)-sinx*sin(π/6)
sinx=1/4
cosx=√15/4
cos(π/6)=√3/2
sin(π/6)=1/2
cos(x+π/6)=(√15/4*√3/2)-(1/4*1/2)
cos(x+π/6)=(√45/8)-(1/8 )
cos(x+π/6)=(√45-1)/8)

6 0

3 years ago