Question

I need help with algebra 2a

Answer 1

`\bf \displaystyle\sum\limits_(j=1)^(10)~2j+7\implies \displaystyle\sum\limits_(j=1)^(10)~2j+\displaystyle\sum\limits_(j=1)^(10)~7\implies 2\displaystyle\sum\limits_(j=1)^(10)~j+\displaystyle\sum\limits_(j=1)^(10)~7 \\\\\\ 2\cdot \cfrac{10(10+1)}{2}~~+~~(10)(7)\implies 2\cdot 55+70\implies 110+70\implies 180`

Answer 2

31

Explanation: