Answer:
3 2/5 cups remaining
Step-by-step explanation:
To subtract fractions, they need a common denominator. I am using 5.
7 is equal to 35/5. Make 3-3/5 into an improper fraction of 18/5.
Now subtract: 35 - 18 = 17. There is 17/5 remaining.
Make it into a mixed number and you will get 3 2/5 remaining.
Answer:
5-9i
Step-by-step explanation:
If you add the 4 and 1 you get 5, and if you add -7i and -2i since they are both negative, they stay negative, so you get -9i. So the answer is 5-9i.
I think the probability that Gwen will reach in her book bag purple eraser is 5/20 or 1/4
Answer: 490 grams of the first alloy should be used.
30 grams of the second alloy should be used.
Step-by-step explanation:
Let x represent the weight of the first alloy in grams that should be used.
Let y represent the weight of the second alloy in grams that should be used.
A chemist has two alloys, one of which is 15% gold and 20% lead. This means that the amount of gold and lead in the first alloy is
0.15x and 0.2x
The second alloy contains 30% gold and 50% lead. This means that the amount of gold and lead in the second alloy is
0.3y and 0.5y
If the alloy to be made contains 82.5 g of gold, it means that
0.15x + 0.3y = 82.5 - - - - - - - - - - - -1
The second alloy would also contain 113 g of lead. This means that
0.2x + 0.5y = 113 - - - - - - - - - - - - -2
Multiplying equation 1 by 0.2 and equation 2 by 0.15, it becomes
0.03x + 0.06y = 16.5
0.03x + 0.075y = 16.95
Subtracting, it becomes
- 0.015y = - 0.45
y = - 0.45/- 0.015
y = 30
Substituting y = 30 into equation 1, it becomes
0.15x + 0.3 × 30 = 82.5
0.15x + 9 = 82.5
0.15x = 82.5 - 9 = 73.5
x = 73.5/0.15
x = 490
X-7=13
move -7 to the right side of the equation, change the sign from negative to positive when you move it
x-7+7=13+7
x=13+7
x=20
