Answer:
-2
Step-by-step explanation:
7x-21-10x+20=5
7x-10x-1=5
-3x=5+1
x=-6/3
x=-2
Step-by-step explanation:
You have miscopied the second equation as it contains a third variable B when there isn't a B in the answers.
Please correct it for assistance
Answer:
and 
Step-by-step explanation:
Alright, lets get started.
The given equation is :

Adding 8 in both sides, it will become


To make it perfect square, we need to add 25 and subtract 25




Adding 17 in both sides
taking square root

So,
and
.. Answer
Hope it will help :)
Take the coefficient of the x-term, half it, then square that. add this to both sides
x² + 16x. coefficient of x is 16. half of 16 is 8. 8²=64
x² + 16x + 64 =64. this is your answer but to continue
x² + 16x + 64 = 64
(x+8)² = 64
x+8 = ✓64
x+ 8 = ±8
x = 0 or -16