Answer
$6y-18$, $-5b+15$
Work Step by Step
The distributive property holds that $a(b+c)=ab+ac$.
A. Therefore, $6(y-3)=(6\times y)+(6\times-3)=(6y)+(-18)=6y-18$.
In this example, the student has forgotten to distribute the 6 to the second term in parentheses.
B. Therefore, $-5(b-3)=(-5\times b)+(-5\times-3)=(-5b)+(15)=-5b+15$.
In this example, the student has forgotten that multiplying the negative number outside of the parentheses by the negative second term will result in a positive product.