Answer:
not rational
Step-by-step explanation:
Given :
An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 50 g of an alloy containing 12% copper with 78 g of an alloy containing 92% copper.
To Find :
How many grams of copper are in the resulting mixture what percentage of the resulting mixture is copper.
Solution :
Mass of copper in 50 gm alloy =
.
Mass of copper in 78 gm alloy =
.
Total mass of copper, ( 6 + 76.44 ) gm = 82.44 gram.
Percentage of copper in resulting mixture :

Hence, this is the required solution.
Answer:
Step-by-step explanation:
Without brackets, we are not exactly sure what is under the root sign. There are 3 choices.
sqrt(x) + 2 - 15 = - 3
sqrt(x + 2) - 15 = - 3
sqrt(x + 2 - 15) = - 3
I think the middle one is what you intend. If not leave a note.
sqrt(x + 2) - 15 = - 3 Add 15 to both sides.
sqrt(x + 2) - 15+15 = - 3+15 Combine
sqrt(x + 2) = 12 Square both sides
x + 2 = 12^2 Do the right
x + 2 = 144 Subtract 2 from both sides.
x + 2-2 = 144-2
x = 142
Is it subtract 228? if so then 3-5 equals -2. -2-8 equals -10. -10-228 equals -238