2(x-3)=7x-31
2x-6=7x-31
-7x -7x
----------------
-5x-6=-31
+6 +6
--------------
-5x=-25
Divide by -5
x=5
3x-2(x+5)=-3+18
15
3x-2(x+5)=15
3x-2x-10=15
x-10=15
+10 +10
--------------
x=25
Answer:
A. 605 mL of the 35% solution
B. 55 mL of the 95% solution
Step-by-step explanation:
It is given that, you need 660 mL of a 40% alcohol solution. On hand, you have 35% alcohol mixture. You also have a 95% alcohol mixture.
Let x and y be the amount of 35% alcohol solution and 95% alcohol solution (in mL) respectively.
So,
Amount equation:
...(1)
Alcohol equation :
...(2)
On solving (1) and (2), we get
Now, substitute y=55 in (1).
Therefore, we need 605 mL of the 35% solution and 55 mL of the 95% solution.
Let's call the 13¢ stamps a and the 18¢ stamps b:
a+b = 42 and therefore a= 42-b (formula 1)
0.13a+0.18b= 6.66 In this formula, substitute the value of a according to formula 1:
0.13(42-b)+0.18b= 6.66 Multiply on the left to get rid of the parenthesis:
5.46-0.13b+0.18b= 6.66 Subtract 5.46 from both sides:
-0.13b+0.18b= 1.20 Add on the left:
0.05b= 1.20 Divide both sides by 0.05
b= 24 You have 24 18¢ stamps and:
42-24= 18 13¢ stamps
Check: (24 x 0.18) + (18 x 0.13)= 6.66 Correct.
Answer:
A
Step-by-step explanation:
Measure of major arc=360°-135° (since one circle adds up to 360)
Major arc=225°
Answer:
its most likely CORRECT!
just have confidence that your answers are correct :)