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cluponka [151]
3 years ago
9

(2x + 7y = -2418x+y=12 solve by substitution​

Mathematics
1 answer:
const2013 [10]3 years ago
4 0

Answer:

x = .87, or when approximated to a fraction, 27/31

y = -3.67, or when approximated to a fraction, -1287/350

Step-by-step explanation:

Lets start by rewriting out our equations

2x + 7y = -24

18x + y = 12

Lets solve for a y value; the second equation is easiest, as the y value has no coefficient (the number that is multiplied times a variable). To do this, lets move the 18x to the other side. Now our two equations look like:

2x + 7y = -24

y = -18x + 12

Next, lets plus the second equation into the first equation in regards to y.

2x + 7(-18x + 12) = -24

Now, lets solve!

2x -126x + 84 = -24

Then, combine your terms!

-124x = -108

Divide by (-124)!

x = -108/-124

x = 27/31

Now that we know x, lets plug this back in to the first equation to find y!

2(27/31) + 7y = -24

1.74 + 7y = -24

7y = -25.74

y = -3.67, or when approximated to a fraction, -1287/350

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djverab [1.8K]

Answer:

<h2>D. points A and B</h2>

Step-by-step explanation:

Look at the picture.

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Find the zeros of each function by using a graph and a table f(x)=x^2+3x-18.
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1) Finding the zeros of this function f(x) =x² +3x -18

f(x) = x²+3x-18 <em>Factoring this equation, and rewriting it</em>

<em />

<em>Which two numbers whose sum is equal to 3 and their product is equal to 18?</em>

<em>6 -3 = 3 and 6 *-3 = -18</em>

<em />

<em>So we can rewrite as (x +6) (x-3)</em>

<em> </em>

(x+6)(x-3)=0 <em>Applying the Zero product rule, to find the roots</em>

x+6=0,

x=-6

x-3=0,

x=3

S={3,-6}

2) Setting a table, plugging in the values of x into the factored form: (x-6)(x-3)

x | y |

1 | -14 (1 +6)(1-3) =-14

2 | -8 (2 +6)(2-3) =-8

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1 year ago
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------------------------------------------------------
Rachel needs to pay $1816.88 for FICA tax
------------------------------------------------------
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At a local coffee shop, three coffees and two muffins cost a total of $7.00. Two coffees and four
rewona [7]

Answer:

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Step-by-step explanation:

Set up a system of equations, so 3c + 2m = 7 and 2c + 4m = 8, where c = the cost of coffees, and m = cost of muffins

To solve multiply the first equation by -2(3c + 2m=7) so you get -6c -4m = -14 now add the two equations

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So now solve the final problem 6(1.50) + 1(1.25) = $10.25

6 0
2 years ago
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