All categories

3 years ago

How can I solve systems of equations by substitution method

1 answer:

5 0

This kind of hard to explain without an example, so I'll do my best...
All you have to do is isolate a variable on one side of the equals sign without a coefficient. Ex: x=2y+3 The x is all alone and ready to go into the second equation.
Substitute into the second equation. Ex: 2x+5=3 Substitute: 2(2y+3)+5=3
I hope this helps!

You might be interested in

1) Are the following lines parallel, perpendicular, or neither?

Maru [420]

In 1)

Line 1 has following coordinates.
(0,0) ; (1,-2) ; (2,-4)

Line 2 has following coordinates.
(0,0) ; (1,0.5) ; (2,1)

Line 3 has following coordinates.
(0,1) ; (1,1.5) ; (2,2)

If you'll draw the lines, you'll observe that Line 1 is perpendicular to Line 2 and Line 3 and Line 2 and Line 3 are parallel to each other.

So,
Option D will be correct.

5 0

3 years ago

For which function is f(x) equal to f^1(x) ( answer choices in picture )

Sonja [21]

Answer:

C. $f(x)=\frac{x+1}{x-1}$

Step-by-step explanation:

Let's find the inverse of each of the given options.

Option A:

$f(x)=\frac{x+6}{x-6}\\y=\frac{x+6}{x-6}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+6}{y-6}$

Rewrite in terms of 'y'. This gives,

$x(y-6)=y+6\\xy-6x=y+6\\xy-y=6x+6\\y=\frac{6x+6}{x-1}$

The given function $y=\frac{6x+6}{x-1}\ne y=\frac{x+6}{x-6}$

So, option A is incorrect.

Option B:

$f(x)=\frac{x+2}{x-2}\\y=\frac{x+2}{x-2}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+2}{y-2}$

Rewrite in terms of 'y'. This gives,

$x(y-2)=y+2\\xy-2x=y+2\\xy-y=2x+2\\y=\frac{2x+2}{x-1}$

The given function $y=\frac{2x+2}{x-1}\ne y=\frac{x+2}{x-2}$

So, option B is incorrect.

Option C:

$f(x)=\frac{x+1}{x-1}\\y=\frac{x+1}{x-1}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+1}{y-1}$

Rewrite in terms of 'y'. This gives,

$x(y-1)=y+1\\xy-x=y+1\\xy-y=x+1\\y=\frac{x+1}{x-1}$

The given function $y=\frac{x+1}{x-1}\ equals\ y=\frac{x+1}{x-1}$

So, option C is correct.

Option D:

$f(x)=\frac{x+5}{x-5}\\y=\frac{x+5}{x-5}$

To find $f^{-1}(x)$ , replace 'x' with 'y' and 'y' with 'x'. This gives,

$x=\frac{y+5}{y-5}$

Rewrite in terms of 'y'. This gives,

$x(y-5)=y+5\\xy-5x=y+5\\xy-y=5x+5\\y=\frac{5x+5}{x-1}$

The given function $y=\frac{5x+5}{x-1}\ne y=\frac{x+6}{x-6}$

So, option D is incorrect.

Therefore, only option C is correct.

7 0

3 years ago

In the equation t = 0.7n - 1.3, the dependent variable

Mila [183]

Answer:

The dependent variable is n i think because the hwole problem depends on n

Step-by-step explanation:

3 0

3 years ago

Please help me. <br><br><br>2 (a + 4) =

vitfil [10]

Answer:

2a+8

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

What is the solution to this equation? <br> 3x-x+8+5x-2=10

Kaylis [27]

3x - x + 8 + 5x - 2 = 10

combine like terms on the left, then add or subtract as asked
(3x - x + 5x) + (8 - 2) = 10

7x + 6 = 10
subtract 6 from both sides

7x = 4
divide both sides by 7

x = 4/7

Hope this helps! :)

7 0

3 years ago