Answer:
10a^2 - 30b
Explanation:
-2(4a^2 - 3[4a^2 - (5b + a^2)]
We have three brackets in the expression, so we open the brackets after the other
Step1: let's open
[ 4a^2 - ( 5b + a^2)]
Open the bracket with - (minus)
- * 5b = -5b
- * +a^2 = -a^2
= [4a^2 - 5b - a^2]
Step 2: open the bracket
( 4a^2 - 3[4a^2 - 5b - a^2]
Open the bracket with -3
-3 * 4a^2 = -12a^2
-3 * -5b = + 15b
-3 * -a^2 = +3a^2
= (4a^2 - 12a^2 + 15b + 3a^2)
Step 3 : open the final bracket
-2(4a^2 - 12a^2 + 15b + 3a^2)
-2 * 4a^2 = -8a^2
-2 * -12a^2 = + 24a^2
-2 * + 15b = -30b
-2 * + 3a^2 = -6a^2
= -8a^2 + 24a^2 - 30b - 6a^2
Step 4: collect the like terms
= -8a^2 + 24a^2 - 6a^2 - 30b
= 10a^2 - 30b