1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
stellarik [79]
3 years ago
15

Solve the system of equations x+4y=15 2x-y=-15

Mathematics
1 answer:
Lady_Fox [76]3 years ago
7 0

x+4y=15 2x-y=-15


We have to make x neg.


-2(x) + 4y (-2)= -2(15)


-2x-8y=-30

2x-y=-15


-9y= -45


Solve for y


Y=-45/-9


Y = 5

Substitute your y answer into one original equation to find x .


x+4y=15


X+4(5)=15


X+20=15


X=15-20


X= -5


Answer is (-5,5)

You might be interested in
PLEASE HELP ASAP
dexar [7]

Answer:

A.-4x^2y^4

that the answer

3 0
2 years ago
Point Y is in the interior of ∠XWZ. Given that WX→ and WZ→ are are opposite rays, and m∠XWY=4(m∠YWZ) is m∠YWZ?.
EleoNora [17]

Answer:

m∠YWZ=36°

Step-by-step explanation:

Opposite rays are two rays that both start from a common point and go off in exactly opposite directions. Because of this the two rays (WX and WZ) form a single straight line through the common endpoint W.

If rays WX and WZ are opposite, then angle XWZ is straight angle. A straight angle always has the measure of 180°.

Point Y is in the interior of ∠XWZ, then angles XWY and EWZ are supplementary angles (together form straight angle XWZ). Supplementary angles always add up to 180°, then

m∠XWY+m∠YWZ=180°

You are given that

m∠XWY=4(m∠YWZ).

Substitute it into the previous equality:

4(m∠YWZ)+m\angle YWZ=180°

5(m∠YWZ)=180°

m∠YWZ=36°

5 0
3 years ago
The perimeter of equilateral triangle ABC is 81/3 centimeters, find the length of the radius and apothem.
MAXImum [283]

There is a typo error, the perimeter of equilateral triangle ABC is 81/√3 centimeters.

Answer:

Radius = OB= 27 cm

Apothem = 13.5 cm

A diagram is attached for reference.

Step-by-step explanation:

Given,

The perimeter of equilateral triangle ABC is 81/√3 centimeters.

Substituting this in the formula of perimeter of equilateral triangle =3\times\ side

3\times\ side =[tex]81\sqrt{3}

Side = \frac{81\sqrt{3} }{3} =27\sqrt{3} \ cm

Thus from the diagram , Side AB=BC=AC= 27\sqrt{3} \ cm

We know each angle of an equilateral triangle is 60°.

From the diagram, OB is an angle bisector.

Thus \angle OBC = 30°

Apothem is the line segment from the mid point of any side to the center the equilateral triangle.

Therefore considering ΔOBE, and applying tan function.

tan\theta =\frac{perpendicular}{base} \\tan\theta=\frac{OE}{BE} \\tan\theta=\frac{OE}{\frac{27\sqrt{3}}{2}  } \\tan30\times {\frac{27\sqrt{3} }{2} }= OE\\\frac{1}{\sqrt{3} } \times\frac{27\sqrt{3} }{2} =OE\\

Thus ,apothem  OE= 13.5 cm

Now for radius,

We consider ΔOBE

cos\theta=\frac{base}{hypotenuse} \\cos30= \frac{BE}{OB} \\Cos30 = \frac{\frac{27\sqrt{3} }{2}}{OB}  \\OB= \frac{\frac{27\sqrt{3} }{2}}{cos30} \\OB= \frac{\frac{27\sqrt{3} }{2}}{\frac{\sqrt{3} }{2} } \\OB =27 \ cm

Thus for

Perimeter of equilateral triangle ABC is 81/√3 centimeters,

The radius of equilateral triangle ABC is 27 cm

The apothem of equilateral triangle ABC is 13.5 cm

4 0
3 years ago
Which is a prime number 21 23 25 27 29
UNO [17]

Answer:

29 :)

it is 29 because 29 falls under all the prime number characteristics

8 0
3 years ago
The ratio to isabella's money to shane's money is 3:11 if isabella has $33 how much money do shane and isabella have together us
alexgriva [62]
Shane and Isabella have 154 dollars
4 0
3 years ago
Other questions:
  • Round 17.62114537 to the nearest tenth
    13·1 answer
  • Is 0.9 <,>,or = to 4/25
    15·1 answer
  • What does x equal in x+4=2x-3
    12·1 answer
  • Factor the numbers<br> x^{2} + 13x +36
    8·1 answer
  • A 6 inch personal pizza has 590 calories, with 240 of those from fat. A 16 inch pizza is cut into 8 slices. Estimate the number
    10·1 answer
  • Please help me solve
    15·1 answer
  • Cereal originally Cost three dollars. The store has reduce the price by 25%. You have a coupon for additional 20% off the alread
    15·2 answers
  • Use a proportion and the conversion to convert between metric and customary units.
    6·1 answer
  • 6 hats for $45 what was the cost per hat ​
    12·2 answers
  • A chemist calculated that the amount of baking soda required for an experiment is between
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!