Need help!! I don’t know the answer in red. It's not 2.

Answer: a=-8 and b=-2
Step-by-step explanation:
What is simple form of [tex]\sqrt[3]{x^{10} }[/tex]
= [tex]\sqrt[3]{(x^{9})(x) }[/tex]
Now, When x = -2
Comparing [tex] a\sqrt[3]{b}[/tex] with [tex] x^{3}\sqrt[3]{x} [/tex]
We get,
[tex] a = x^{3} [/tex]
[tex] a = -8[/tex]
Now, [tex] b = x = -2 [/tex]