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
Juli2301 [7.4K]
3 years ago
14

Solve the system by substitution x=-8y-15 2x+5y=-8

Mathematics
2 answers:
lidiya [134]3 years ago
8 0
2(-8y-15)+5y=-8
-16y-30+5y=-8
-11y-30=-8
+30 +30
-11y=22
—- —-
-11 -11
y=-2
x=-8(-2)-15
x=16-15
x=1

(1,-2)
Ghella [55]3 years ago
3 0

To solve this system by substitution, we must substitute in the value we are given for x in terms of y (the first equation) into the second equation.  This is modeled below:

x = -8y - 15

2x + 5y = -8

2 (-8y - 15) + 5y = -8

Now, we should solve this new equation for y.  To begin, we should use the distributive property to get rid of the parentheses on the left side of the equation and begin the simplification process.

-16y - 30 + 5y = -8

Next, we can combine like terms on the left side of the equation by adding together the two terms that both contain the variable y.

-11y - 30 = -8

Next, we should add 30 to both sides in order to move all of the constant (number) terms to the left side of the equation.

-11y = 22

After that, we should divide both sides of the equation by -11 in order to get the variable y alone.

y = -2

Now, we can substitute our value for y back into one of our original equations (it doesn't matter which one you choose; they will yield the same answer).

x = -8y - 15

x = -8(-2) - 15

To simplify, we should following the order of operations outlined by PEMDAS and compute the multiplication and then the subtraction.

x = 16 - 15

x = 1

Therefore, the answer to the system is x = 1 and y = -2, or (1,-2) when written as an ordered pair.  

Hope this helps!

You might be interested in
The number of trees in a rainforest decreases each month by 0.5%. The forest currently has 2.5 billion trees. Which expression r
Blababa [14]

Answer:

y=2.5*10^9(0.005^{12 0}) \\\\

Step-by-step explanation:

The above question is in the form of an exponential decay. The equation for an exponential decay is given by:

y=ab^x

where y and x are variables, b < 1, a is the initial value of y (that is the value of y when x = 0).

Let y represent the number of trees left and x represent the number of months. Given that there is currently 2.5 billion trees, therefore a = 2.5 * 10⁹, b = 0.5% = 0.005. The equations becomes:

y=2.5*10^9(0.005^x)\\\\After\ ten\ years(x=10*12\ months=120\ months):\\\\y=2.5*10^9(0.005^{12 0}) \\\\

8 0
3 years ago
2.Pleas can someone answer!
kenny6666 [7]

Answer: A, A, C

Step-by-step explanation:

Educated Guess because none of them are going to be zero so it's either A or C but the point has a negative y so to plug it all in all of them have to be negative ex. -1 + -1 + -1 =-3

the x is -1 so both have to be negative in order to get -3

5 0
3 years ago
I don't know I try my best I'm not good at this
AlladinOne [14]
You should definitely ask your parents or teacher. Also, never give up :)
Trust me just keep trying your best and don't tell yourself that you can't do it :)
8 0
3 years ago
Find the area of this parallelogram.<br><br> 8.9 cm<br> 7.1 cm<br> 11.4 cm
defon
<h3>Answer: 80.94 square cm</h3>

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

Work Shown:

Area of parallelogram = base*height

Area of parallelogram = 11.4*7.1

Area of parallelogram = 80.94 square cm

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

notes:

  • The base and height always form a 90 degree angle (as shown by the small square marker).
  • The side length of 8.9 cm is never used.
  • We can write "square cm" as "cm^2" or \text{ cm}^2
3 0
3 years ago
Read 2 more answers
-8x-10y=24;6x+-10x-10y
stiks02 [169]
Do you have a typo? ;  < this maybe
4 0
3 years ago
Other questions:
  • A certain type of automobile battery is known to last an average of 1140 days with a standard deviation of 80 days. If 400 of th
    13·1 answer
  • Ivan's has 3/4 pound of hamburger meat. She makes 3 hamburgers patties.each patty weighs the same amount.hiw much dies each hamb
    13·2 answers
  • HELLLP JUST GIVE THE ANSWER
    8·2 answers
  • F(x)=3x^3-12x^2+9x what the factor<br>​
    15·2 answers
  • H(0)=
    10·1 answer
  • Aina must choose a number between 61 and 107 that is a multiple of , 23, and 9 .
    8·1 answer
  • Who can help with this?
    13·1 answer
  • Write an equation of the line that passes through (0,−5)<br> and (−5,−5)<br> .
    15·1 answer
  • A baker bakes 50 muffins. 1/5 of the muffins are chocolate chip. 1/2 of the muffins are blueberry. The rest are cinnamon. How ma
    13·1 answer
  • Look at the photo I’m about to have to math class i need help! I’ve got 15 mins!
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!