Đáp án:
Giải thích các bước giải:
a, F( x ) `=` `5` `+ 3`$x^{2}$ - x - 2$x^{2}$
f( x ) `=` ( `3`$x^{2}$ - `2`$x^{2}$ ) - x + `5`
f( x ) `=` `1` $x^{2}$ - x `+ 5`
________________________________________________________________________
g( x ) `=` `3`x `+ 3` - x - $x^{2}$
g( x ) `=` - $x^{2}$ +`(` `3`x - x `) + 3`
g( x )`=` $x^{2}$ `+` `2`x `+ 3`
________________________________________________________________________
b, h( x ) `=` f ( x ) + g( x )
=) h( x ) `=` ($x^{2}$ `+ 2`x `+ 3)` `+ (1`$x^{2}$ - x `+ 5 )`
=) h ( x ) `=` $x^{2}$ `+ 2`x `+ 3 + 1`$x^{2}$ - x `+ 5`
=) h ( x ) `=` ( 1$x^{2}$ + $x^{2}$ ) `+ ( 2`x - x `) + ( 3 + 5 )`
=) h ( x ) `=` `2` $x^{2}$ `+ 1x + 8`
