\(x-11=7\)

Add 11 to both sides: \(x-11+11=7+11\)

Simplify: \(\boxed{x=18}\)

\(x^2+13^2=85^2\quad :\quad x=84,\:x=-84\)

It's helpful if you add the link.

\(\log _2\left(3\right)\log _3\left(4\right)\log _4\left(5\right)\log _5\left(6\right)\log _6\left(7\right)\log _7\left(8\right)=\boxed3\)

This may be helpful.

Note: Please put on-topic titles to make it easier for others to find.

\(\mathrm{Slope-Intercept\:form\:of}\:15x-6y=48:\quad y=\frac{5}{2}x-8\)

\(\textcolor{red}{\text{redacted}}\)

Easier to read: The numbers \(1,-1\) and \(a+1\) are the roots of the equation \(x^3+6x^2-2bx-3c-12=0\). Find the values of \(a,b,c\).

Easier to understand: A creature on the moon throws a rock off a cliff. the height of the rock above the surface of the moon, in meters, \(t\) seconds after it is thrown is given by \(h(t) = -t^2 +8t +10\). when does the rock hit the surface of the moon?

Hm, make an acct and message (web2.0calc.com/messagecenter/cryptoaops). talk like that instead.