Question 628270
3+√(z-11) = √(z+4)
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{{{3 + sqrt(z-11) = sqrt(z+4)}}}
Square both sides
{{{9 + 6sqrt(z-11) + (z-11) = z+4}}}
{{{6sqrt(z-11) = 6}}}
Square again
36(z-11) = 36
x-11 = 1
z = 12