Answer: -2
Step-by-step explanation:
When x = 1, y = -2.
Hope it helps <3
Here is one way to solve for x.
Step 1) 2x^2-7=9
Step 2) 2x^2-7+7=9+7
Step 3) 2x^2=16
Step 4) (2x^2)/2=16/2
Step 5) x^2=8
Step 6) sqrt(x^2)=sqrt(8)
Step 7) |x|=sqrt(8)
Step 8) x=sqrt(8) or x=-sqrt(8)
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Below are explanations/reasons to each of the steps above.
Step 1) Original equation
Step 2) Add 7 to both sides
Step 3) Combine like terms
Step 4) Divide both sides by 2
Step 5) Simplify
Step 6) Apply the square root to both sides. The notation "sqrt" is shorthand for "square root"
Step 7) Use the rule that sqrt(x^2) = |x| for all real numbers x
Step 8) Use the rule that if |x| = k then x = k or x = -k for some fixed number k.
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The two solutions are
x = sqrt(8) or x = -sqrt(8)
Answer: 2/3 of an hour.
Step-by-step explanation: The constant rate of the lifeguard filling the pool is 1/3 of the pool every 1/2 hour. If she fills it for an hour, she'll get 2/3 of the pool filled. Therefore, it'll take the lifeguard 1 hour to fill the pool 2/3 of the way.
Hope this helps! :)
Answer:
Step-by-step explanation:
the formula for density is:
where d is density, m is mass, and V is volume.
solving for m in the last equation:
so if we find the volume and multiply it by the density 
we will get the mass of the object.
The volume of a rectangular prism is given by:
where 
is length, 
is width and 
is height:
we substitute to find the volume:
since the density has units of 
we need the volume also in units of , so we make the conversion using:
multiplying by 30:
and now we find the mass with the equation:
substituting d and V:
the nearest gram is:
