solve for x

Question

solve for x

anonymous · Answer

attachment

zephyr141 · Answer

lol all of that?

anonymous · Answer

no just 7-10

anonymous · Answer

you sure?

kl0723 · Answer

how about explaining how this is done instead of just throwing random answers... just saying

zephyr141 · Answer

agreed. it's a site to help with homework not do your homework.

anonymous · Answer

can someone walk me trough how to do #7 so i can do the rest

anonymous · Answer

beware of answers that come with no explanation
they are often wrong

anonymous · Answer

$$2\sqrt{x+2}-3=7$$ go to get the racial by itself first

anonymous · Answer

add $3$ to get 
$$2\sqrt{x+2}=10$$ then divide by $2$ and get 
$$\sqrt{x+2}=5$$

anonymous · Answer

lol "radical" not "racial"

anonymous · Answer

now that you have $$\sqrt{x+2}=5$$it should be routine
square and get $x+2=25$ making $x=23$

zephyr141 · Answer

remember that all the adding/subtracting/dividing/multiplying is happening on both sides of the equation.

anonymous · Answer

okay and i have to type my work so how do you get that square root thing

anonymous · Answer

and thanks this helped a lot

zephyr141 · Answer

i think it would be understandable if you wrote "SQRT( number )" doesn't necessarily need to be capitalized.

anonymous · Answer

oh okay

anonymous · Answer

yeah i would use sqrt(x+2)=5 for example

zephyr141 · Answer

@satellite73 i think 9 and 10 will have two answers for x?

zephyr141 · Answer

right?

anonymous · Answer

does it?

zephyr141 · Answer

yeah you have to use the quadratic equation or just factoring it.

anonymous · Answer

sqrt(7-3x)=1
sqrt(7-3x)^2=(1)^2
7-3x=1
3x=-6
x=2

anonymous · Answer

so thats right for #2

zephyr141 · Answer

yup. good job!

anonymous · Answer

yay!

zephyr141 · Answer

but don't forget the negative sign on the 3x in that second to last step. it can bite you if you forget it.

anonymous · Answer

okay haha

anonymous · Answer

and for number 3 do i just so the same thing or do i need to do something extra since i have that little 3 in front

zephyr141 · Answer

a square root is just your quantity to the 1/2 power. we take it to the second power because of the rules of exponents where $$(x^a)(x^b)=x^{ab}$$ so when you take that 1/2 power and multiply it by 2 you have $$\frac{ 1 }{ 2 }*2$$ which just becomes one. now for number 3 you have the quantity to the cubed root. so that means it's to the 1/3 power. now how do you eliminate the 1/3 power? by raising it to the cubed root.

zephyr141 · Answer

so think of it like this $$\sqrt[3]{3x-1}=(3x-1)^{\frac{ 1 }{ 3 }}$$