Answer:
[tex]\large\boxed{-2(10r+4)+10(7r+2)=50r+12}[/tex]
Step-by-step explanation:
[tex]-2(10r+4)+10(7r+2)\qquad\text{use the distributive property}\ a(b+c)=ab+ac\\\\=(-2)(10r)+(-2)(4)+(10)(7r)+(10)(2)\\\\=-20r-8+70r+20\qquad\text{combine like terms}\\\\=(-20r+70r)+(-8+20)\\\\=50r+12[/tex]
