Answer:
[tex]10x-56 + 6x^{2}[/tex]
Step-by-step explanation:
Step 1: [tex]4x-16+2(3x^{2} +3x-20)[/tex]
Step 2: [tex]4x-16+6x^{2} +6x-40[/tex]
Step 3: [tex](4x+6x) + (-16-40) +6x^{2}[/tex]
Step 4: [tex]10x - 56 + 6x^{2}[/tex]
