Answer: [tex]9m=10[/tex] or [tex]m=\frac{10}{9}[/tex]
I don't know your options... but you can check my work below and see if any of the other options fit yours.
Step-by-step explanation:
[tex](x^2 + 3)2 + 7x^2 + 21 =10[/tex]
If [tex]x^2+3=m[/tex], we can rewrite this as;
[tex](m)2+7x^2+21=10\\2m+7x^2+21=10[/tex]
By grouping, we can factor another m.
[tex]2m+(7x^2+21)=10[/tex]
Factor a 7.
[tex]2m+7(x^2+3)=10[/tex]
Rewrite it in terms of m.
[tex]2m+7m=10[/tex]
Combine like terms;
[tex]9m=10[/tex]
Divide by 9
[tex]m=\frac{10}{9}[/tex]
