Answer:

Step-by-step explanation:
Answer:
A. in Step 3
Step-by-step explanation:
It is factored correctly. Then separated into two smaller equations correctly. But in solving x + 10 = 0, there is an error.
x + 10 = 0
Add -10 to both sides.
x = -10
So, the error is in step 3.
Add all shapes area together to know the figures complete area
triangles area 1 & 2 : 6×8 /2 -> 48/2 = 24
rectangle 1 : 6×12 -> 72
rectangle 2 : 8×12 -> 96
rectangle 3 : 10×12 -> 120
24+72+96+120
96+96+120
192+120
312cm