To find a+ib=−8−6i​−5−12i​+5+12i​​ and calculate 2a+b :Calculate −5−12i​ and 5+12i​ :Since the real parts of −5−12i​ and 5+12i​ are positive:−5−12i​=213−5​​+i213+5​​=2−3i5+12i​=213+5​​+i213−5​​=3+2iCalculate −8−6i​ :Given that the real part is negative:−8−6i​=−210−8​​+i210+8​​=−1+3iFind a+ib: Using the calculations from the previous steps:a+ib=−1+3i(2−3i)+(3+2i)​=−1+3i5−i​Multiply the numerator and the denominator by the conjugate of the denominator:=(−1+3i)(−1−3i)(5−i)(−1−3i)​Simplify:=1+9−5+i−15i−3​=10−8−14i​=−54​−57i​Thus, a=−54​ and b=−57​.Calculate 2a+b :2a+b=2(−54​)+(−57​)=−58​−57​=−3Hence, the result is -3 .