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3 years ago

Solve the system of equations. – 5x + 2y = 9 y = 7x X = Y =

Mathematics

2 answers:

Helen [10]3 years ago

6 0

Answer:

x = 1

y = 7

Step-by-step explanation:

Your system of equations is

-5x + 2y = 9

y = 7x

The easiest way to solve this is by substitution. This means that you set one of the equations equal to a variable and you plug that variable into the variable of the other equation. The second equation (y = 7x) is already set up this way so we will plug it into the first equation.

-5x + 2(7x) = 9

-5x + 14x = 9

9x = 9

(9x)/9 = (9)/9

x = 1

You have found x. Now, plug this number into the second equation (y = 7x) to find the value of y.

y = 7(1)

y = 7

Sphinxa [80]3 years ago

5 0

Answer:

x−y = 9 , x + y = 6

x + y = 4 , x − y = 2

x + 2 y = 4 , x − y = − 3

try out these examples?

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3 years ago

Let g(x) = 2x and h(x)= x^2 -4. find (g o h)(0)

finlep [7]

The answer is -8

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

Explanation:

There are two ways to get this answer

Method 1 will have us plug x = 0 into h(x) to get
h(x) = x^2 - 4
h(0) = 0^2 - 4
h(0) = 0 - 4
h(0) = -4
Then this output is plugged into g(x) to get
g(x) = 2x
g(-4) = 2*(-4)
g(-4) = -8 which is the answer
This works because (g o h)(0) is the same as g(h(0)). Note how h(0) is replaced with -4
So effectively g(h(0)) = -8 which is the same as (g o h)(0) = -8

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

The second method involves a bit algebra first
Start with the outer function g(x). Then replace every x with h(x). On the right side, we will replace h(x) with x^2-4 because h(x) = x^2-4

g(x) = 2x
g(x) = 2( x )
g(h(x)) = 2( h(x) ) ... replace every x with h(x)
g(h(x)) = 2( x^2-4 ) ... replace h(x) on the right side with x^2-4
g(h(x)) = 2x^2-8
(g o h)(x) = 2x^2-8

Now plug in x = 0
(g o h)(x) = 2x^2-8
(g o h)(0) = 2(0)^2-8
(g o h)(0) = 2(0)-8
(g o h)(0) = 0-8
(g o h)(0) = -8

Regardless of which method you use, the answer is -8

5 0

4 years ago

I need help with this question really quick!!!

dimulka [17.4K]

Answer:

Np buddy its B. Hope u get a good grade

5 0

3 years ago

ashley spends $12 to buy 3 pencils and 6 rulers. Jack spends $8 to buy 5 pencils and 2 rulers. what is the cost of 2 pencils and

Sveta_85 [38]

Answer:

$ 3 left ashley money

$ 1 left jacks money

$ 8 left ashley money

$ 4 left jacks money

Step-by-step explanation

3 pencils + 6 rulers = 12 - 9 = 3

5 pencils + 2 rulers = 8 - 7 = 1

12 - 4 = 8

8 - 4 = 4

6 0

3 years ago

Read 2 more answers

It says factor each expression 49x-28?

NARA [144]

Answer:

7(7x -4)

Step-by-step explanation:

49x-28

We can factor a 7 from each term

49x = 7*7x

28 = 7*4

7(7x -4)

3 0

4 years ago