Question Of The Day

Solve |||||x2 – x – 1|-2| -3| -4|-5| = x2 + x – 30.  

a) 2 + √2

b) 2√2

c) 7½

d) none of these

Ans: c) 7½

Ihs ≥ 0, so x2 + x ≥ 30, so x ≥ 5 or ≤ -6. Hence x2 – x ≥ 20, so we do not need the absolute value signs and lhs = x2 – x – 15. Hence x = 7.1/2.