Question

I have to combine all the variable but I don't understand how with the decimals

Answer 1

$\bf 2.25-11j-7.75+1.5j=0.5j-1\qquad \begin{array}{rllll} -7.75\\ 2.25\\ ---\\ -5.50 \end{array}\qquad \begin{array}{rllll} -11.0j\\ 1.5j\\ ---\\ -9.5j \end{array} \\\\\\ -9.5j-5.5=0.5j-1\implies -9.5j-0.5j=5.5-1 \\\\\\ \begin{array}{rllll} -9.5j\\ -0.5j\\ ---\\ -10.0j \end{array}\qquad \begin{array}{rllll} 5.5\\ -1.0\\ ---\\ 4.5 \end{array}\implies -10j=4.5\implies j=\cfrac{4.5}{-10} \\\\\\ j=-0.45$