unknown

Yeah thanks! just got confused with the two x's.

the answer is x=5

(32-12=20. 20/4=5)

You can do a screenshoot and crop it

In the calculator, just put the fraction as a division problem in parenthaces

example, 3 tenths is (3/10)

on the forum, most people know what you mean if you say 3/10

Ok, so it's talking about laser beams.

"Two additional lazer beams are added to the design. The path of the beams can be modeled by the linear equations 7x+3y=21 and -7x+3y+21. Graph these beams below."

1/3x=-7

You have to get rid of 1/3 to get x alone, but have to make both sides equal. Divide both sides by 1/3

$${\mathtt{\,-\,}}{\frac{{\mathtt{7}}}{\left({\frac{{\mathtt{1}}}{{\mathtt{3}}}}\right)}} = -{\mathtt{21}}$$

x=-21

4/5 is 8/10, because 4*2= 8 and 5*2=10 

8/10. 8 tenths. .8 or .800

The weight of 10 to the power of 7 dust particles is 1 gram. Simplify 10 to the 7 power

the first part is unneeded and is just a distraction

10^7 = 10*10*10*10*10 *10*10=10000000

10^anything will always be 1 followed by that number of zeros

a to the 2 divided by a to the second cancels out

-4/3a-a^2/a^2-5a+6

a^2- 5a= a*a-a*a*a*a*a=-3a

-4/3a-a^2/3a+6

3a-a^2= a*a*a-a*a=1a or a

-4/a/3a+6

-4+6=2

2/a/3a

i think thats as far as i can get

ok sorry if i get this wrong. i am not a math teacher and you may want to check my work.

equvilent equations means have the same varabiles, so solving for n will give you the answer.

lets get n by itself

-6n-20=-2n+4(1-3n)

take away 4 from both sides

-6n-20-4=-2n(1-3n)

add 6n to boths sides

20-4=-2n(1-3n)+6n

subtract one from each side

20-4-1=-2n(3n)+6n

solve left side

15=-2n(3n)+6n

Divide both sides by 6 

2.5=-2n(3n)+n divide both sides by 3 5/6=-2n(n)+n

divide both sides by -2 -5/12=n(n)+n lets name these n's  1,2, and 3 (for this step only) based on left to right order (easier to explain)

1 and 3 can be combined into 2n so you get

-5/12=2n(n) divide 2 from each side -5/24=(n)

That took a long time. i hope i'm correct. make sure to subisitute in -5/24 for n in the original problem