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
Gekata [30.6K]
2 years ago
5

I'm solving systems and I don't understand how to do it pls helpp

Mathematics
2 answers:
kaheart [24]2 years ago
8 0

Answer:

Use the process of elimination. I'll only do one example since you have 4.

Step-by-step explanation:

Let's do the first question.

2x-3y=-11

2x+y=9

Our goal here is to be left with one variable to solve, this way we can use the answer for that variable to find the other. A.K.A only find X to plug into the equation to find Y. To do this, we'll use the process of elimination, in which we need to cancel out a variable.

X seems the easiest here. To cancel 2 (in the top equation), you need to have a -2. And that -2 needs to be the x coefficient in the 2nd equation, in order for us to "cancel" it out. To get -2, you multiply 2 by -1.

-1(2x+y)= -1(9)

Note that whatever you do to one side, you need to do it to both sides! Hence, why I also multiplied 9 by -1. You should now be left with:

-2x -y = -9

Now, we cancel out the positive 2 and -2 from both equations by adding the two equations.

2x-3y= 11

+

-2x-y=-9

X cancels out, so we're left with -4y=-20. Solve for Y, which is 5.

-4y=-20

y=5

Now that you have the Y value, plug it into any of the two equations to find your X value.

2x-3y=11

2x-3(5)=11

2x-15=11

2x=26

x=13

And voilah! Our Y value is 5, and our X value is 13.

It's pretty simple once you understand what's going on. All that we did was to cancel out one variable (either X or Y) in the two equations so that we're left with only one variable to solve. If we cancel out X, we only need to solve for Y. You do this by manipulating one of the two equations (doesn't matter which one). Once you find either X or Y, all you need to is to plug it into one of the original equations. Then, you'll have both X and Y.

And that my friend, is the process of elimination. Good luck!

makvit [3.9K]2 years ago
6 0
Nzkbxaibzeugey was
You might be interested in
Given the system of equations presented here:
Nata [24]
2x + 4y = 14
4x + y = 20......multiply by -4
----------------
2x + 4y = 14
-16x - 4y = -80 (result of multiplying by -4)
---------------add
-14x = -66....as u can see, ur y's cancel out

so ur answer is : 1st answer choice <==

** and just so u know, u could have multiplied the 1st equation by -2, and it would have cancelled out ur x's
6 0
3 years ago
Is -8x + 10 = 2(5-4x) one solution
Basile [38]
The answer to this is true
3 0
3 years ago
Please answer ASAP! Due 2/11/2020
mojhsa [17]
2) 5= 7 + -2
3) (-8) + 8 = 0
8) 3 + 5 = 8
9) 7 + 5 = 12
10) 4 = -8 + 4
8 0
3 years ago
ANT
ExtremeBDS [4]

Answer:

Algebra Examples

Popular Problems Algebra Find the Axis of Symmetry f(x)=x^2-5 f(x)=x2−5 Set the polynomial equal to y to find the properties of the parabola. y=x2−5

Rewrite the equation in vertex form.

y=(x+0)2−5 Use the vertex form,  y=a(x−h)2+k, to determine the values of a, h, and k.a=1h=0k=−5

Since the value of a is positive, the parabola opens up.

Opens Up

Find the vertex

(h,k).(0,−5)

Find p, the distance from the vertex to the focus.

14 Find the focus.

(0,−194)

Find the axis of symmetry by finding the line that passes through the vertex and the focus.

x=0

3 0
2 years ago
In 1990, 1000 adults were randomly selected and each was asked if they smoked, 300
Oduvanchick [21]

Answer:

 The proportion of smokers was higher in 1990 than in 2000

Step-by-step explanation:

Solution

Recall that,

The total number of sample 1 (n1) = 1000

Total  sample 2 number  (n2) = 2000

The number of favourable events (X1) = 300

The number of favourable events (X2) = 500

so,

p₁ = X₁/n₁ = 300/1000 = 0.3

p₂ = X₂/n₂ =500/2000 =0.25

α = 0.05

We are interested in testing the hypothesis.

The  hypothesis (Null) ....>  H₀ : p₁ = p₂

Alternate hypothesis------ > H₁ : p₁ > p₂

Thus,

P = X₁ + X₂/ n₁ + n₂

P =300 + 500/1000 +2000

P =800/3000

=0.2667

Now,

Z₀ = P₁ - P₂/√ P (1 -P) (1/n₁ + 1/n₂)

Z₀ =  0.3 - 0.25/√0.2667  (1 - 0.2667) (1/1000 + 1/2000)

Z₀ = 0.4999999999999999/√ 0.2667 (0.7333000000000001) (0.001 +0.0005)

Then,

Z₀ = 0.4999999999999999/√0.00029335666500000004

Z₀ = 2.9193

so,

zα/2 = z0.05/2 =z0.025

zα/2 = 1.6448536269514722

Now, we apply the decision rule:

Decision Rule: Reject the null hypothesis if the statistic value test is higher than the critical value 1.6448536269514722

The statistic value, 2.9193 is greater than the critical value 1.6448536269514722,  then we will reject the null hypothesis.

Therefore, the proportion of smokers was higher in 1990 than in 2000

3 0
3 years ago
Other questions:
  • How would I solve this?
    7·1 answer
  • Please help !!!!find a0 when a15=82 and d=3
    7·1 answer
  • Use the diagram to find each angle measure.Explanation added please.
    5·1 answer
  • What are the roots of the polynomial equation?
    15·1 answer
  • Please answer quickly
    13·1 answer
  • Two quadratic functions are shown.
    9·2 answers
  • Two buses leave towns 339 miles apart at the same time and travel toward each other. One bus travels 13 mi/h slower than the oth
    15·1 answer
  • The scale drawing of a playground is 4 cm wide and 6 cm long. The playground is 14 m wide. How long is it?
    15·1 answer
  • Use trigonometric ratios to find the indicated side
    15·1 answer
  • Can someone pls simplify this<br><img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B105%7D%7B12%7D%20" id="TexFormula1" title=" \fra
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!