Algebrahard · Past Paper
Solve: sqrt(x + 5) = x - 1.
A4
B-1
C4, -1
D5
✓ Correct Answer: A — 4
Square both sides: x+5 = x^2-2x+1 => x^2-3x-4=0 => (x-4)(x+1)=0. x=4 works; x=-1 is extraneous as sqrt(4) ≠ -2.
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