Answer:
 750 grams of 60% alloy
Step-by-step explanation:
Define x = amount of 60% alloy and y = amount of 20% alloy
Equating the amounts of gold:
0.6x+0.2y = 1000(0.5)
Since there must be 1000 grams total:
x+y = 1000
Writing the 2 resulting equations together:
0.6x + 0.2y = 500
x + y = 1000
Multiply the first equation by 5:
3x + y = 2500
x + y = 1000
Subtracting the 2nd equation from the 1st:
2x = 1500
x = 750
Answer: 750 grams of 60% alloy
 
        
             
        
        
        
Answer:
144
Step-by-step explanation:
angle A + angle B = 180 (supplementary angle)
A = 4B
4b+b=180
5b=180
Divide 5 on both sides to get b=36
180-36= measure of angle A
180-36=144
 
        
             
        
        
        
Answer:60
Step-by-step explanation:30%+30%=60% since it is a rectangle i thing this is the answer
 
        
             
        
        
        
Answer:
The answer is 75.
Step-by-step explanation:
Average rate of change = Δy/Δx
y^2 -  y^1/x^2 - x^1 
925 - 400/12 - 5 = 525/7 = 75