Answer:
Distributive property
Step-by-step explanation:
The given equation is:
[tex]2q(q+4)=10[/tex]
To solve this equation, we expand the left hand side using the distributive property to obtain:
[tex]2q^2+8q=10[/tex]
That was exactly what Miskai did.
Therefore the property that justifies his step shown is the distributive property.
This property says that, if a, b, and c are real numbers then,
[tex]a(b+c)=ab+bc[/tex]
