All categories

2 years ago

2y=-x+93×-6y=-15 whats the solution to the system

Mathematics

2 answers:

liq [111]2 years ago

8 0

Answer:

Step-by-step explanation:

2y = -x +9

3x - 6y = -15

The solution is the value of x and y that will make the two equations true in the same time.

3x-6y = -15; divide both sides by 3

x-2y = -5; substitute 2y for -x+9 because the first equation tell us they are equal

x-(-x+9) = -5; open parenthesis

x+x-9 = -5 ; add 9 to both sides and combine like terms

2x = -5 +9; 2x = 4; divide both sides by 2

x= 2

Substitute x for 2

2y = -x+9 ; 2y = -2 +9 ; 2y = 7; y = 7/2 = 3.5

Solution is (2, 3.5)

astraxan [27]2 years ago

3 0

Answer:

(2, 7/2)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtract Property of Equality

Algebra I

Coordinates (x, y)
Terms/Coefficients
Solving systems of equations using substitution/elimination

Step-by-step explanation:

Step 1: Define Systems

2y = -x + 9

3x - 6y = -15

Step 2: Rewrite Systems

2y = -x + 9

[Division Property of Equality] Divide 2 on both sides: y = -x/2 + 9/2

Step 3: Redefine Systems

y = -x/2 + 9/2

3x - 6y = -15

Step 4: Solve for x

Substitute in y: 3x - 6(-x/2 + 9/2) = -15
Distribute -6: 3x + 3x - 27 = -15
Combine like terms: 6x - 27 = -15
[Addition Property of Equality] Add 27 on both sides: 6x = 12
[Division Property of Equality] Divide 6 on both sides: x = 2

Step 5: Solve for y

Define original equation: 2y = -x + 9
Substitute in x: 2y = -2 + 9
Add: 2y = 7
[Division Property of Equality] Divide 2 on both sides: y = 7/2

You might be interested in

You are fundraising for the schools track team by selling clothing. The first day, you sell 13 t-shirts and 17 pairs of shorts f

Anastasy [175]

Answers:

one t-shirt costs $10

one pair of shorts costs $15

============================================================

Explanation:

x = cost of one t-shirt

y = cost of one pair of shorts

13x+17y = 385 is the first equation because 13x represents the money you get from selling 13 shirts, and the 17y represents the amount you get from selling 17 shorts. The total 13x+17y is given to be $385

The second equation is 13x+12y = 310 for similar reasoning, but this time you sell 12 shorts this time and you get $310 in revenue.

The system of equations we have is:

$\begin{cases}13x+17y = 385\\13x+12y=310\end{cases}$

There are a few ways to solve this system. Possibly the quickest method is to note that the 13x shows up twice, so we can subtract straight down to eliminate the x terms

So,

13x-13x becomes 0x or just 0, and the x terms go away.
17y-12y becomes 5y
385-310 becomes 75

After those three subtractions, we have the equation 5y = 75 which solves to y = 15 after dividing both sides by 5. This means the cost of one pair of shorts is $15

Plug this y value into any equation involving x and y, and solve for x

13x+17y = 385

13x+17(15) = 385

13x+255 = 385

13x = 385-255

13x = 130

x = 130/13

x = 10

Therefore, each t-shirt costs $10

-----------------

To help verify the answer, plug (x,y) = (10,15) into each equation. We should end up with a true result after simplifying both sides.

Start with the first equation