Answer:
.....Which is the required answer.
Explanation:

Bianca wants to multiply the equation below by 3
So she can solve a system of linear equations with the elimination method.
To Find:
What will the new equation be once she multiplies?
Solution:

Multiply the above equation through out by 3 we get

Applying Distributive Property i.e A(B+C)=AB + AC we get

.....Which is the required answer.