Answer:
(x+5)²-10x²
Step-by-step explanation:
USing the completing square method
x² +25
= (x)² +2(x)(5) +(5)² -10x²
=(x+5)²-10x²
Answer:

Step-by-step explanation:

Answer:
-0.55n - 0.05
Step-by-step explanation:
You can start by distributing:
(0.25n - 0.3) - (0.8n - 0.25)
0.25n - 0.3 - 0.8n + 0.25
Then, you can combine like terms(0.25n & -0.8n; -0.3 & 0.25)
-0.55n - 0.05
Abd is a right angled triangle so by pythagoras we know

and to calculate h we need to use the sine rule

i hope this helps