Please explain more your question
<span>Answer:
MgF2 ====⇒ Mg+2 + 2F-
Ksp = [Mg+2][F-]^2
Let S = molar solubility of MgF2
[Mg+2] = S ; [F-] = 2s
Since the [F-] is initially 0.40 M, then [F-] = 0.40 + 2S
6.4 x 10^-9 = (S) (0.40 + 2S)^2 ; one can neglect the 2S in the 0.40 + 2S expression since it is very, very small compared to the 0.40 already present.
6.4 x 10^-9 = S(0.40)^2
S = 4.0 x 10^-8
Molar solubility = 4.0 x 10^-8</span>
Wait so are the sides of the octagon 9 inches each or do we have to find that?
<span>This is the equation made from the problem where x=mystery number
</span><span>2x+3(x+1)=4(x-1)</span><span>
</span><span>Now let's solve for x!
</span><span>
</span><span>We start by distributing 3 into (X+1)
</span><span>
</span><span>3(x)=3x and 3(1)=3
</span><span>
</span><span>Now our equation is 2x+3x+3=4(x-1)
</span><span>
</span><span>Let's combine both x values on the left side of the equation: 2x + 3x=5x
</span><span>
</span><span>We now have 5x+3=4(x-1)
</span><span>
</span><span>Let's distribute 4 into (x-1)
</span><span>
</span><span>4(x)=4x and 4(-1)=-4
</span><span>
</span><span>Now our equation is 5x+3=4x-4
</span><span>
</span><span>subtract 3 form both sides
</span><span>
</span><span>5x=4x-7
</span><span>
</span><span>subtract 4x from both sides
</span><span>
</span><span>x=-7
</span><span>
</span><span>Yay! So the number she is thinking of is -7!</span><span>
</span>
Take the decimal and multiply it by 100.
