5. −6+i−5+i
Multiply the numerator and denominator by -5 - i .
=(−6+i)(−5−i)(−5+i)(−5−i)=30+6i−5i−i225+5i−5i−i2=30+i−i225−i2
Replace the i2 's with -1 since i2 = -1
=30+i−(−1)25−(−1)=30+i+125+1=31+i26
6. 12x2−x+5=0
We can use the quadratic formula to solve this for x, with a = 1/2 , b = -1 , and c = 5 .
x=−(−1)±√(−1)2−4(12)(5)2(12) x=1±√1−101 x=1±√−9 x=1±i√9
5. −6+i−5+i
Multiply the numerator and denominator by -5 - i .
=(−6+i)(−5−i)(−5+i)(−5−i)=30+6i−5i−i225+5i−5i−i2=30+i−i225−i2
Replace the i2 's with -1 since i2 = -1
=30+i−(−1)25−(−1)=30+i+125+1=31+i26
6. 12x2−x+5=0
We can use the quadratic formula to solve this for x, with a = 1/2 , b = -1 , and c = 5 .
x=−(−1)±√(−1)2−4(12)(5)2(12) x=1±√1−101 x=1±√−9 x=1±i√9