Answer:
4[tex]\sqrt{14}[/tex]
Step-by-step explanation:
Using the rule of radicals
[tex]\sqrt{a}[/tex] × [tex]\sqrt{b}[/tex] ⇔ [tex]\sqrt{ab}[/tex]
Simplify radicals, that is
[tex]\sqrt{56}[/tex]
= [tex]\sqrt{4(14)}[/tex]
= [tex]\sqrt{4}[/tex] × [tex]\sqrt{14}[/tex] = 2[tex]\sqrt{14}[/tex]
[tex]\sqrt{126}[/tex]
= [tex]\sqrt{9(14)}[/tex]
= [tex]\sqrt{9}[/tex] × [tex]\sqrt{14}[/tex] = 3[tex]\sqrt{14}[/tex]
Then
[tex]\sqrt{56}[/tex] - [tex]\sqrt{14}[/tex] + [tex]\sqrt{126}[/tex]
= 2[tex]\sqrt{14}[/tex] - [tex]\sqrt{14}[/tex] + 3[tex]\sqrt{14}[/tex]
= 4[tex]\sqrt{14}[/tex]
