Answer:
84 ounces of pure gold
Step-by-step explanation:
Jess has 60 ounces of an alloy that is 40% gold. How many ounces of pure gold must be added to this alloy to create a new alloy that is 75% gold?
Pure gold = 100% gold
Let the number of ounces of pure gold = x
Hence, we have the equation
40% × 60 ounces + 100%× x ounces = 75%(60 + x)ounces
= 0.4 × 60 + 1x = 0.75(60 + x)
= 24 + x = 45 + 0.75x
Collect like terms
x - 0.75x = 45 - 24
0.25x = 21
x = 21/0.25
x = 84 ounces
Therefore, we need 84 ounces of pure gold
Answer:
c
Step-by-step explanation:
Answer:
x=1±√47
Step-by-step explanation:
it's up above.
Answer:
30, 85, 95, 150
Step-by-step explanation:
The angles of a quadrilateral add to 360
Let x be the smallest angle
x+55
x+65
x+120 are the other three angles
Add the 4 angles together and they sum to 360
x+x+55 x+65+ x+120 = 360
Combine like terms
4x+240 = 360
Subtract 240 from each side
4x+240-240 = 360 -240
4x = 120
Divide by 4
4x/4 = 120/4
x = 30
x+55= 30+55 = 85
x+65 = 30+65 = 95
x+120 = 30+120 = 150
Maybe three units is the answer
