Answer: x>9
Step-by-step explanation:
3 < x/2+1
switch sides: x/2+1 > 3
Multiply sides by 3: 3x/2+1 > 3*3
Simplify: x>9
Answer: D. 12h + 21h2
Step-by-step explanation: The answer is D,
because when you devide 12h/3h = 4
and for the other value 21h2/3h=7h
4 + 7h
if you perform the same operation with the rest of answers you will get a minor values if you compare with this results, because of that the answer with the greatest common factor is D.
Step-by-step explanation:
first a little help, how they got the equations :
in total they need 15 liters.
so, whatever x and y are, but together they must be 15 L.
x + y = 15
then, we are mixing x liters of 20% alcohol with y liters of 100% alcohol, that have to result in a 40% solution of (x+y) liters :
0.2x + y = 0.4(x+y)
we know from the first equation that x+y = 15, so the second equation is actually
0.2x + y = 0.4 × 15 = 6
so, we have
x + y = 15
0.2x + y = 6
do you notice something ? there is a "+ y" in both equations.
so we can actually subtract the second equation from the first, eliminate y and solve for the remaining x. and then use one of the original equating to get also y :
x + y = 15
- 0.2x + y = 6
---------------------
0.8x 0 = 9
0.8x = 9
x = 9/0.8 = 11.25 liters
x + y = 15
11.25 + y = 15
y = 15 - 11.25 = 3.75 liters
