Answer:
1128
Step-by-step explanation:
Math
Answer:

Step-by-step explanation:
8x+9=0
8x=-9

or

,



, 
Answer:
5.2%.
Step-by-step explanation:
After 1 hour (60 / 100) * 700 = 420 gallons of beer have been exchanged.
So we have 420 gallons of 6% and 280 gallons of 4% after 1 hour.
So the strength at that time = (420* 6) + 280*4) / 700
= 5.2%.
Answer:
one solution
Step-by-step explanation:
* Lets start to solve the question
- The 1st equation x - y = -4
- The 2nd equation 3x + y = 8
- We will use the elimination method to solve this system of equation
∵ x - y = -4 ⇒ (1)
∵ 3x + y = 8 ⇒ (2)
- Add the two equation (1) and (2) to eliminate y
∴ x + 3x = -4 + 8
∴ 4x = 4
- Divide both sides by 4
∴ x = 1
- Substitute the value of x in equation (1) or equation (2) to find
the value of y
- We will use equation (1)
∴ 1 - y = -4
Subtract 1 from both sides
∴ -y = -5
- Divide both sides by -1
∴ y = 5
∴ The solution is (1 , 5)
* The system has one solution