Answer:
600 L of 30% proof and 400 L of 80% proof is needed
Step-by-step explanation:
Let the amount of 30% smell proof be x while that of 80% smell proof is y
Then;
x + y = 1000 •••••(i)
Also;
30% of x + 80% of y = 50% of 1000
0.3x + 0.8y = 500 •••••(ii)
From i, x = 1000 - y
Put this into ii
0.3(1000-y) + 0.8y = 500
300 - 0.3y + 0.8y = 500
0.5y = 500-300
0.5y = 200
y = 200/0.5
y = 400 L
But x = 1000 - y
x = 1000 - 400 = 600 L
It is different because you are doing a different method to complete the problem. It is the same because it ends up with the same answer, provided you complete the process correctly.
Let us bear in mind the equivalent value of these coins:
One dime = $0.10
One quarter = $0.25
Let x = number of dimes
y<span> = number of quarters</span>
Since the boy has 70 coins in total, we can say that:
<span>x + y = </span><span>70 </span>(can be written as x = 70 – y)
Since the boy has a total of $12.40, we can say that:
0.10x + 0.25y = 12.40
To solve this problem, we need to solve this system of equation. We have to substitute the value of x as written in the first equation (x = 70 –y)
0.10(70 – y) + 0.25y = 12.40
7 – 0.10y + 0.25y = 12.40
0.15y = 5.40
y = 36
X = 70 – 36
X = 34
Therefore,<span> the boys </span>has<span> 34 dimes and 36 quarters. To check our answer, we just have to check if his money would total $12.40.</span>
34 dimes = $3.40
36 dimes = $9.00
<span>Total </span><span>$12.40</span>
Answer:
n=-6
Step-by-step explanation:
2(n+5)=-2
distribute
2(n+5)
2xn 2x5
2n+10
2n+10=-2
subtract 10 from both sides
10-10=0
-2-10=-12
2n=-12
divide each side by 2
2n/2=n
-12/2=-6
n=-6
