Just use PEMDAS 
2+3-4 (5x4) 
Parenthesis
Exponents 
Multiplication
Division
Addition 
Subtraction    So first is Parenthesis 5x4=20 next will be Addition because there are no exponents 2+3= 5-4= 1 so now we go back to multiplication 20 x 1= 20 so 20 is your answer. 
Hope I helped out ^^
        
             
        
        
        
Answer:
2,8
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x=-1
Step-by-step explanation:
2x+3/4(4x+16)=7
2x+(3x12)=7--->distributive property
2x+3x+12=7
5x+12=7--->addition property
5x=-5--->subtraction peroperty
x= -1---?division property
 
        
             
        
        
        
Answer:
r = 3 1/4
Step-by-step explanation:
Here, we want to find the value of r given the values 
Firstly, we will write r as the subject of the formula 
U = π ( r + h) 
U/π = r + h
r = U/π - h 
Now substitute;
U = 16 1/2 = 33/2
h = 2
π= 22/7 
r = 33/2/22/7 - 2
r = (33/2 * 7/22) - 2
r = 21/4 - 2
r = (21-8)/4
r = 13/4 = 3 1/4
 
        
             
        
        
        
The volume at time <span>t = 25 seconds
since </span><span> V = 4 sqrt(t) cm3, 
 V(5)= 4*</span><span>sqrt(25)cm^3=4*5=20cm^3</span>