Answer: 4,000
Step-by-step explanation:
Create a table. Multiply across and add down (you cannot add the middle column). The bottom row will produce an equation.
Let x represent the panels that Plant B produced.
[tex]\begin{array}{c|c|c||c}&\underline{Quantity}&\underline{\% De fective}&\underline{Quantity\times \%\ De fective}\\Plant\ A&6000&6\%=0.06&6000(0.06)=360\\\underline{Plant\ B}&\underline{\qquad x\qquad }&\underline{1\% = 0.01}&\underline{x(0.01)=0.01x}\\\text{Mixture}&6000+x&4\%=0.04&360+0.01x\end{array}\\\\\\(6000+x)(0.04)=360+0.01x\\.\qquad 240+0.04x=360+0.01x\\.\qquad 240+0.03x=360\\.\qquad \qquad \quad 0.03x=120\\.\qquad \qquad \qquad \quad x=\large\boxed{4,000}[/tex]