Answer:
No
Step-by-step explanation:
6a + 12 =? 3(3a + 4)
Distribute
6a+12 =? 3*3a + 3*4
6a+12 =? 9a +12
No
The expressions are not equivalent
Answer:
25 cent stamps = 13 and 29 cent stamps = 15
Step-by-step explanation:
x = 25 cent stamps and y = 29 cent stamps
x + y = 28......x = 28 - y
0.25x + 0.29y = 7.60
0.25(28 - y) + 0.29y = 7.60
7 - 0.25y + 0.29y = 7.60
-0.25y + 0.29y = 7.60 - 7
0.04y = 0.60
y = 0.60 / 0.04
y = 15 <===== 29 cent stamps
x + y = 28
x + 15 = 28
x = 28 - 15
x = 13 <===== 25 cent stamps
lets check it...
0.25x + 0.29y = 7.60
0.25(13) + 0.29(15) = 7.60
3.25 + 4.35 = 7.60
7.60 = 7.60 (correct..it checks out)
Answer: it will take them about 24 minutes working together
Step-by-step explanation:
1/40 + 1/60 =
6/240 + 4/240 = 10/240 = 1/24
1/24 = 1/t
Cross multiplication:
1*t = 1*24
t= 24
Let 
be the volume of 20% solution, 
the volume of the 60% solution. We want a total volume of 400 mL in the final mixture, so
Each mL of either solution will contribute a corresponding concentration, and in the final mixture we want the 400 mL to have a 40% concentration, which means we should also have
Solve the system and we get 
.
Yes you are correct. You divide both sides by -6 to isolate x. Dividing both sides by a negative number will flip the inequality sign.
If you need to graph this, then you'll have a closed circle at -12 on the number line. Then you'll have shading to the left of this closed circle. The closed circle indicates "include this endpoint as part of the shaded solution set".
