<span>7r²+9=1
</span><span>the equation is contradictory, just to prove
7r</span>² + 9 = 1
7r² + 9 -1 = 0
7r² + 8 = 0
<span>We write the equation in the form of products of
</span>
7 * (r² + 8/7) = 0
<span>the product is equal to 0 when one of the factors is zero
</span>
7≠0 ∨ (r² + 8/7) = 0
r² ≠ - 8/7
<span>any number squared is not negative.
</span><span>We proved that none of the factors is not equal to zero , so the right side of the equation is not equal to the left . The equation is contradictory</span>
Step-by-step explanation:
i think its
b=<u>x</u>
<u> </u><u> </u><u> </u><u> </u><u>a</u>
<u>h</u><u>o</u><u>p</u><u>e</u><u> </u><u>i</u><u>t</u><u> </u>help<u> </u><u>u</u><u>.</u><u>.</u><u>.</u>
Check the picture.
let the length of a side of each of the squares removed be x.
The box formed will have dimensions: 80-2x, 50-2x, x(the height)
So the volume can be expressed as a function of x as follows:
f(x)=(80-2x)(50-2x)x=
![[4000-160x-100x+4 x^{2} ]x=(4 x^{2}-260x+4000)x](https://tex.z-dn.net/?f=%5B4000-160x-100x%2B4%20x%5E%7B2%7D%20%5Dx%3D%284%20x%5E%7B2%7D-260x%2B4000%29x)
so

the solutions of f'(x)=0 gives the inflection points, so the candidates for maxima points,

solving the quadratic equation, either by a calculator, graphing software, or by other algebraic methods as the discriminant formula, we find the solutions
x=10 and x=33.333
plug in f(x) these values to see which greater:

cm cubed

which is negative because (50-66.666)<0
Answer: 18000 cm cubed
Remember, in order for this equation to be true either one of the polynomials has to equal 0
So:
-> x+6 = 0
x=-6
-> 2x-5 = 0
2x= 5
x= 5/2
So the answer is x=-6 and x= 5/2.
Hope this helps!
Factor out -1
-1(x^2+x-6)
Factor the inner trinomial
-1(x+3)(x-2)
Final answer: B