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Rasek [7]
3 years ago
12

A little difficult question for me, it is multiple choice answer but my teacher taught this before the break. If anyone could he

lp me that would be wonderful.

Mathematics
1 answer:
Sever21 [200]3 years ago
7 0
<h3>Answer: Choice D</h3>

Divide both sides of the first equation by 7, then add the result to the second equation

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

Explanation:

We can multiply both sides of an equation by the same number and the equation will be equivalent to the original.

For example, if we had  x = 5, then we could get 2x = 10 after multiplying both sides by 2. The reason they are equivalent equations is because the same x value is the solution for both equations.

We can also divide both sides of an equation by the same number and the two equations would be equivalent. We can go from 2x = 10 back to x = 5 when we divide both sides by 2.

----------

If we divide both sides of 7x - 21y = 14 by 7, then we end up with x - 3y = 2. Simply divide each term (7x,  -21y, and 14) by 7.

Because 7x-21y=14 and x-3y=2 are equivalent, this means we can replace the "7x-21y=14" with "x-3y=2"

--------

The new system would be

x-3y = 2

2x+3y = 11

From here you add straight down. Doing so will have the y terms add to -3y+3y = 0y = 0. After this point the y terms are eliminated and you can solve for x just like with any other equation of one variable.

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F(x)=11(-4)^2-5(-4)+13<br> =-143<br> (-4, -143)???
lora16 [44]

Answer:

(-4,169)

Step-by-step explanation:

11 (-4)^2 - 5(-4)+13

11(16)- 20 +13

176 -20+13

169

7 0
3 years ago
You want to find the mean weight of the apples in a barrel. what do you need to do?
Sveta_85 [38]
If you want to find the weight of the apples in the barrel first you have to ( FIND THE TOTAL WEIGHT OF ALL THE APPLES AND DIVIDE BY ALL THE NUMBER OF APPLES)
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3 years ago
I need help with this problem
Misha Larkins [42]
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4 0
2 years ago
A store is having a sale on walnuts and chocolate chips. For 7 pounds of walnuts and 9 pounds of chocolate chips, the total cost
Jlenok [28]

Answer:

  • Walnuts  cost $1.75, chocolate chips cost $2.75

Step-by-step explanation:

<h3>Let the costs be:</h3>

  • Walnuts - x
  • Chocolate chips - y

<h3>Set equations as per question</h3>

For 7 pounds of walnuts and 9 pounds of chocolate chips, the total cost is $37:

  • 7x + 9y = 37

For 5 pounds of walnuts and 3 pounds of chocolate chips, the total cost is $17:

  • 5x + 3y = 17

<h3>Solve the system by elimination</h3>

Multiply the second equation by 3 and subtract the first equation, solve for x:

  • 3(5x + 3y) - (7x + 9y) = 3(17) - 37
  • 15x + 9y - 7x - 9y = 51 - 37
  • 8x = 14
  • x = 14/8
  • x = 1.75

Find the value of y:

  • 7*1.75 + 9y = 37
  • 12.25 + 9y = 37
  • 9y = 37 - 12.25
  • 9y = 24.75
  • y = 24.75/9
  • y = 2.75
6 0
2 years ago
What is the value of x^2 divided by y^4 when x=8 and y=2
7nadin3 [17]

Answer:

4

Step-by-step explanation:

64/16=4

7 0
3 years ago
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