Answer
a. $-3j^2 + 5j - 7k$
b. $12a - 53b$
Work Step by Step
a. Let's first group like terms:
$(-4j^2 + j^2) - 7k + 5j$
Now, we can combine like terms:
$-3j^2 + 5j - 7k$
b. Let's use the opposite of a sum property first to simplify the first part of the expression:
$-8a - 3b + 10(2a - 5b)$
Use the distributive property for subtraction to simplify the second part of the expression:
$-8a - 3b + 20a - 50b$
Group like terms:
$(-8a + 20a) + (-3b - 50b)$
Combine like terms:
$12a - 53b$
