Answer:
firstly you should have a clear concept about algebra
secondly you should know some basic formula
hope it helps you
 
        
             
        
        
        
Original Price = $20
Discount = 40%
First Calculate the discount amount by multiplying the original price (20) by the percentage discount in decimal form ( divided by 100)
20 x (40/100) = 20 x 0.4 = 8
Then subtract the discount amount to the original price:
20-8 = 12
Sale price : $12
 
        
             
        
        
        
Answer:
69 years
Step-by-step explanation:
Given that:
Let year of birth = x
This year = 2020
Year of 25th birthday = x + 25
Year of 55th birthday = x + 55
Present age = 2020 - x
Hence, 
x + 2020 - (x + 25 + x + 55) + (2020 - x) = 58
x + 2020 - (2x + 80) + (2020 - x) = 58
x + 2020 - 2x - 80 + 2020 - x = 58
-2x + 4040 - 80 = 58
-2x + 3960 = 58
-2x = 58 - 3960
-2x = - 3902
x = 1951
Birth year = 1951
,
Hence, age =
2020 - 1951 = 69 years 
 
        
             
        
        
        
N = 4
(3)(4)-(2+4) = 12 - 6 = 6
        
             
        
        
        
Answer:
the answer is 19
Step-by-step explanation:
you have to multiply the two numbers