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
Pavel [41]
3 years ago
11

Solve system of equation algebraically y = 2x - 3 x + y = 18

Mathematics
2 answers:
Troyanec [42]3 years ago
8 0

Answer:

X=3 Y=15

Step-by-step explanation: First you need to use the problem 18/2=x to find the value of x. Now to find the value of y, you need to subtract 3 from 18.  Then you solve

15=2(9)-3 15+3=18

natima [27]3 years ago
3 0

Answer:

x = 7

y = 11

Step-by-step explanation:

Given the system;

y = 2x - 3

x + y = 18

1. Approach

The easiest way to solve this system of equations is to solve the second equation for the variable (y). Then add the systems, use algebra to solve for the value of (x), then substitute that value back into one of the original equations to solve for the value of (y). Another name for the method in use is the method of elimination, this is when a [erspm manipulates one of the equations in a system of the equation such that when they add the equations, one of the variables eliminatates. Thus, they can solve for the other variable and the backsolve for the value of the unknown variable.

2. Solve one of the equations for a variable

Manipulate the system such that each equation is solved for the same variable,

x + y = 18

Inverse operations,

x + y = 18

-18        -18

x + y - 18 = 0

   -y         -y

x - 18 = -y

3. Use elimination

Now substitute this back into the original system,

y = 2x - 3

-y = x - 18

Add the systems,

y = 2x - 3

-y = x - 18

_________

0 = 3x - 21

Inverse operations,

0 = 3x - 21

+21       +21

21 = 3x

/3    /3

7 = x

4. Find the value of the unknown variable

Backsovle to find the value of (y),

x + y = 18

Substitute,

7 + y = 18

Inverse operations,

7 + y = 18

-7        -7

y = 11

You might be interested in
*GEOMETRY*please help me find the surface area of the solid along with the volume of it step by step!
Serjik [45]

Surface area of the solid = 7.1781 in²

Volume of the solid = 0.804 in³

Explanation:

Surface area of the solid = surface area of the square prism - 2(base of the cylinder) + lateral surface of cylinder

surface area of a square prism = 2(lw + lh + wh)

l = length = 1 in

w = length = 1 in

h = height = 1 in

\begin{gathered} \text{Surface area = 2(1}\times1\text{ + 1}\times1\text{ + 1}\times1) \\ \text{Surface area = 2(1 + 1 + 1) = 2(3)} \\ \text{Surface area = 6 in }^2 \end{gathered}

using the value π as it is on the calculator

Base area of a cylinder = πr²

2(Base area of cylinder) = 2πr² = 2π(0.25)² = 0.3927

Lateral surface area = 2πrh = 2π(0.25)(1) = 1.5708

Surface area of the solid = 6 - 0.3927 + 1.5708

Surface area of the solid = 7.178 in²

Volume of the solid = Volume of the square prism - volume of the cylinder

Volume of square prism = length × width × height

length = 1 in, width = 1 in, height = 1 in

Volume of the solid = 1 in × 1 in × 1 in = 1 in³

Volume of a cylinder = πr²h

Volume of the cylinder = π × 0.25 × 0.25 × 1 = 0.196

Volume of the solid = 1 - 0.196

Volume of the solid = 0.804 in³

4 0
2 years ago
17x - 6 + 3x - 5 = x + 11 + 4x<br> simplify
densk [106]

Answer:

The answer is x= 22/15=1,47

Step-by-step explanation:

We put in one member the X and in the other the whole numbers:

17x - 6 + 3x - 5 = x + 11 + 4x

17x +3x -x-4x= 11+6+5

15x = 22

x= 22/15

7 0
4 years ago
Davian is traveling at a constant speed of 85 kilometres per hour. If he is half way through his 510 kilometre trip, how much lo
inna [77]
E.5 hours
All you have to do is subtract 85 from 510 till you have 0
7 0
3 years ago
Read 2 more answers
How would I solve 7r=-7/2? I know the answer is -1/2 I just don't understand how to get -1/2 as my answer.
Art [367]
7r=-7/2

divide both sides by 7 to get r by itself

(7r)/(7) = (-7/2)/(7)

if you don't quite see it, think of multiplying both sides by 1/7 instead (its the same thing as dividing by 7)

(7r)*(1/7)=(-7/2)*(1/7)

r=-1/2
7 0
4 years ago
The Sears Tower in Chicago is 1454 feet high. Sketch and find the angle of elevation from a point 750 feet from the base to the
liq [111]

Answer: A. 62.7

Step-by-step explanation:

Using the Pythagorean Theorem, know the distance from the top of the tower to the spot on the ground 750 feet away is 1636 feet.

Now with all lengths of the triangle we can solve for the angle giving us 62.7169723304

Now we round to the tenth as instructed and get an answer of 62.7

5 0
4 years ago
Read 2 more answers
Other questions:
  • A car company charges $34 per day for a rented car and $0.50 for every mile driven. A second car rental company charges $20 per
    13·1 answer
  • Justin bought 7 oranges at a grocery store. Justin gave the cashier $10 and
    15·1 answer
  • What is the following quotient? Sqrt 96/ Sqrt 8
    15·2 answers
  • Rewrite as a simplified fraction.<br> 0.5 = ?
    6·2 answers
  • PLEASE help! Due today! 15 pts!
    6·1 answer
  • Write 6/8 as a division equation
    5·1 answer
  • Trình bày phương pháp tìm ma trận nghịch đảo bằng phép biến đổi sơ cấp. Áp dụng tìm ma trận nghịch đảo của ma trận
    13·1 answer
  • ~!¡! Attributes !¡!~<br> ~Question 2~<br> (I only have 5)
    10·2 answers
  • 3x + 4y = 18 -2x + 4y = 8 can someone help me out with this?​
    10·1 answer
  • Determine the lateral and surface area of each triangular prism<br><br><br>​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!