#### I need help with substitution method because I still get confused with the negative numbers.

She said to put two equations into one problem, to solve for x and then put x into one of the equations to solve for y.

Anonymous

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If **x** + **y** = **2** and **x 2** + **y 2** = **2** , what is the **value** of **x**

Well **one** way to **solve** it would **be** by squaring the first **equation** and subtracting
the second .... To reach this conclusion you just **need** to try to **solve** it graphically
and Voila! ..... If **2**^**x**+**2**=k, what is the **value** of **x in** SAT math level **2**? ..... **2** so we
can **write 2** instead of **x**^**2**+**y**^**2**. **2**+2xy =4. 2xy = **2**. xy =**1**. I hope it **helps**. Thank **u**.

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If **x** + **y** = 3 & **x 2** + **y 2** = 3 **then** what is the **value** of

As others **have** stated, the simplest way to **solve a** system of **equations** (fancy
math speak for when you ... **In** order to **get x** by itself **on** the left, we **need** to **get** rid
of **y**. ... More terms to **combine** since we **have two y** squared terms. .... If you can
overcome the fear of **a problem** and work through it **one** way, **then a** second path
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Easy interview question **got** harder: given **numbers 1**..100, find the ...

This reduces the **problem** to **solving** the system of **equations** ... c**2** = **a1a2** + **a1a**3
+ . .... Where **x** and **y are** how far the sums **are** below the expected **values**. ... were
missing **in** the initial array of size N-k **are still** missing **in** the extended array). ..... k
is, the **problem** can **be solved in** constant time **because** you can use **a set** and ...

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linear algebra - Is there another simpler **method** to **solve** this ...

Aug 29, 2013 **...** It is **still** the same concept, **but at** this point, the student will think "there must **be a**
better way" which leads to using graphs and algebra to **solve** the same **problem**.
... to **make** tricycles until you **have** 38 wheels (i.e., every time you **add a** ..... we
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algebra precalculus - Finding **two numbers** given their sum and their ...

Here **are a** couple of systematic approaches that work **in** general. ..... The "
standard" **problem** was to find the dimensions of **a** door, given its perimeter and
area. ... We can use the fact that we know how to **solve** quadratic **equations**. ....
The average of **x** and **y** is 16/**2** = 8, their product is xy = 55 therefore: **x**, **y** = 8 plus
or **minus** ...

For more information, see algebra precalculus - Finding **two numbers** given their sum and their ...

Qalaxia Knowlege Bot

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Cubic function - Wikipedia

History[edit]. Cubic **equations** were known to the ancient Babylonians, Greeks,
Chinese, ... The solutions of this equation are called roots of the polynomial f(x).
.... **two problems in** cubic **equations from** Zuanne da Coi and announced that **he**
could **solve** them. .... **a value** that is also important **in solving** the cubic **equation**.

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History of algebra - Wikipedia

Algebra can essentially **be** considered as doing computations similar to those of
arithmetic **but** ... Rhetorical algebra, **in** which **equations are** written **in** full
sentences. ..... dx^{2} - adx + b^{2}c = 0 and the familiar Babylonian **equation** xy = **a ^{2}**,

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Support Vector Machines

We would **then** predict “**1**” **on an** input **x** if and ... **a** decision boundary (this is the
line given by the **equation** θT **x** = 0, and ... asked to **make a** prediction for the
**value** of **y at A**, it seems we should **be** ... to **be** large, we **need** wT **x** + b to **be a**
large **negative** number. .... This optimization **problem** can **be solved** using
commercial.

For more information, see Support Vector Machines

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6 Wave **Equation on an** Interval: Separation of Vari- ables

Plugging **u into** the wave **equation** above, we see that the functions. **X** ... If we
**have** any **negative** eigenvalues, our eigenvalue **problem** becomes. {. **X** ... **Then**
letting un(**x**, t) = Xn(**x**)Tn(t), we will **have** found **a solution** of the wave **equation** ...
For which functions φ, ψ can we find constants **An**,Bn such that we can **write** φ
and ψ.

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Sangeetha Pulapaka

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The substitution method is pretty straight forward, but we have to be more careful when it comes to negative numbers.

Let us say there are two equations

y = -x -2 ---------> equation 1

y = x -4 ---------> equation 2

Now equating the equations across each other we get

-x - 2 = x - 4

Combining the like terms together,

-x -x = 2 - 4

-2x = -2

\frac{-2x}{-2} = \frac{-2}{-2}

x = 1

Now plug in the value of x = 1 in either one of the equations to get the value of y

Plugging it in equation 1 we get

y = -1 -2 = -3

Skills you may want to recall:

What are like terms

http://www.math.com/school/subject2/lessons/S2U2L4DP.html

What are variables

https://www.mathsisfun.com/definitions/variable.html