Answer:
[tex]10 {x}^{2} + ( - 18)[/tex]
Step-by-step explanation:
Inserting fx into gx we get
[tex]5(2 {x}^{2} - 5) + 7[/tex]
Which then becomes
[tex]10 {x}^{2} - 25 + 7[/tex]
And finally the answer is
[tex]10 {x}^{2} - 18[/tex]
