All Answers 358108 Answers

Evaluate  means "find the answer"    

When you made this post there was a sticky topic attached called "How do I type in fractions"

You can still access it - it's with the other sticky topics on the bottom right hand side of this page.

pi equals 3.1417

answer is 3.571428571

$$\\\frac{4}{7}-(-3)\\
=\frac{4}{7}--3$$

Now thinking just about + and - signs

If two signs are so close together that you can put a circle around them without anything else getting in the way THEN if the signs are different then it will be a - and if the signs are the same then it will be a +

  $$Here $--$ is replaced with a $+$$$

You should be able to finish it now  :)

They are trigonometric ratios.  If you google this you will get a lot more info.  

Pi is an irrational number the above answers are approximations.

What is the x in front of the 3 for? 

It depends which calculator,  

Please note that Rosala has simplified this expression.

It cannot be solved because it is not equal to anything  

See if this helps.

Note that we're just subbing "3a" in for "x" .....so we have.......

f(3a) = 3a + 2 

This one is pretty easy.....

We have

sin(60) = opp/ hyp = opp/ 12

So the opposite side - how high the ladder will reach  -  is just   (12*√3) /2 = 6√3 ft. = about 10.4 ft.

There are a few ways to solve this. We can solve this by graphing, elimination, or substitution.

It looks like elimination will be the easiest way to solve this. To solve two equations by elimination, you basically add these two equations together. Let's do this.

    -2x-5y=-6

+   2x-7y=-14

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

        -12y = -20

Now we'll solve for y.

 -12y = -20         ---Multiply both sides by a negative

-(-12y)=-(-20)

12y = 20            ---Divide both sides by 12

y = 20/12           ---reduce the fraction by dividing he top and bottom by 4

y = 5/3

Now we put y in one of the original equations to solve for x. Let's pick the first equation.

-2x-5y=-6 

-2x-5(5/3)=-6 

-2x -25/3= -6                ---Multiply everything by a negative

2x +25/3 = 6               ---subtract 25/3 from both sides

2x = 6 - 25/3

2x = 6/1 - 25/3

2x = 18/3 - 25/3

2x = -7/3                      ---Divide btoh sides by 2

x = -7/3 ÷ 2

x = -7/3*1/2

x= -7/6

Our solution is that x = -7/6, and y = 5/3.

The * means multiply.  

See if this helps. 

One foot is approximately 0.3048 meters. If you square that, you come up with 1 square foot = 0.092903 square meters.

Now set up a proportion:

1 ft² over 0.092903 m² = 1830 ft² over x m²

$${\frac{{\mathtt{1}}}{{\mathtt{0.092\: \!903}}}}$$  =  $${\frac{{\mathtt{1\,830}}}{{\mathtt{x}}}}$$

Cross-multiply:

0.092903 * 1830 = x

x = $${\mathtt{0.092\: \!903}}{\mathtt{\,\times\,}}{\mathtt{1\,830}} = {\mathtt{170.012\: \!49}}$$

x = 170 m²

4-m/2+10

You would simplify it, since it is an expression and not an equation (with an equal sign.) Therefore it would be:

-m/2 + 10 + 4

-m/2 + 14

you have to multiply BEFORE you add or subtract

52-6*3+4

=52-18+4

=34+4

=36

order of operation is very important in maths

See here and then you can to into one of the mathsisfun sites if you want more.

Thanks for that resource, Melody.....I saw this question earlier, but I didn't know how to proceed with a good explanation.....that website looks to be pretty informative......multiplying "by hand" seems to be a lost art !!!!

Look here

Thanks Rosala 

Write the quadratic function whose zeros are:

$$\boxed{
&x^2+px+q=0\quad
\begin{array}{rcll}
-p&=&x_1+x_2&\mbox{[Vieta]}\\
q&=&x_1x_2&\mbox{[Vieta]}
\end{array}

}$$

1. 2+square root of 5, 2-square root of 5

$$\big{
\left\begin{array}{r*{3}{cl}}
-p&=&(2+\sqrt{5})&+&(2-\sqrt{5})& =&4\\
q&=&(2+\sqrt{5})&*&(2-\sqrt{5}) &=&4-5=-1
\end{array}
\right\} x^2-4x-1=0
}$$

2. 3+7i,3-7i

$$\big{
\left\begin{array}{r*{3}{cl}}
-p&=&(3+7i )&+&(3-7i )& =&6\\
q&=&(3+7i )&*&(3-7i ) &=&9-49i^2=58
\end{array}
\right\} x^2-6x+58=0
}$$

3. 5±i

$$\big{
\left\begin{array}{r*{3}{cl}}
-p&=&(5+i )&+&(5-i)& =&10\\
q&=&(5+i)&*&(5-i) &=&25-i^2=26
\end{array}
\right\} x^2-10x+26=0
}$$

Almost anonymous  

$$\\(2x+4)(x-4)\\
=2x^2-8x+4x-16\\
=2x^2-4x-16\\$$

109 is a prime number, so this can't be factored in a real number form!!!!

Also, "factoring" the lead term - x^3 - would involve x and x^2. So we would have an additional "x" term that didn't exist in the original problem......

Thus, this one is irreducible to a factored form.......