Answer:0.3
Step-by-step explanation:
(7x+0.1)+(10x-0.2)= 17x-0.1
17x-0.1=5
17x=5.1
x=5.1/17
x=0.3
Answer:
d
Step-by-step explanation:
If Sandra mixes <em>x</em> L of 65% solution with <em>y</em> L of 90% solution, then the resulting mixture has a total volume of
<em>x</em> + <em>y</em> = 500
litres, and it contains
0.65<em>x</em> + 0.90<em>y</em> = 0.75 (500) = 375
litres of alcohol.
Solve the first equation for <em>y</em> :
<em>y</em> = 500 - <em>x</em>
<em />
Substitute this into the second equation and solve for <em>x</em> :
0.65<em>x</em> + 0.90 (500 - <em>x</em>) = 375
0.65<em>x</em> + 450 - 0.90<em>x</em> = 375
75 = 0.25<em>x</em>
<em>x</em> = 300
Solve for <em>y</em> :
<em>y</em> = 500 - 300
<em>y</em> = 200
So, Sandra should mix 300 L of 65% solution with 200 L of 90% solution.
Answer:
-5 ≤ n ≤ 3
Step-by-step explanation:
Firstly we solve the equation two at a time;
5n + 17 ≥ n - 3
5n - n ≥ -3 - 17
4n ≥ -20
n ≥ -5
-5 ≤ n
n - 3 ≥ -15 + 5n
n - 5n ≥ -15 + 3
-4n ≥ -12
-n ≥ -3
n ≤ 3
Therefore,
5n+17 ≥ n–3 ≥ –15+5n, becomes
-5 ≤ n ≤ 3
