Given that $$\int _ { 0 } ^ { 1 } ( a x + b ) \mathrm { d } x = 1$$ and $$\int _ { 0 } ^ { 1 } x ( a x + b ) \mathrm { d } x = 1$$ find the value of $a + b$.
..... 3
Given that
$$\int _ { 0 } ^ { 1 } ( a x + b ) \mathrm { d } x = 1$$
and
$$\int _ { 0 } ^ { 1 } x ( a x + b ) \mathrm { d } x = 1$$
find the value of $a + b$.