Let c and d be the number of cds and dvds respectively.
c+d=12
c=12-d
The we are told that:
2c+3d=31, using c found above in this equation gives you:
2(12-d)+3d=31
24-2d+3d=31
24+d=31
d=7
So Phillip bought 7 dvds.
check...
3*7+2(12-7)=31
21+2(5)=31
21+10=31
31=31
Answer:
Here, x represents the weekly sale
As per the statement:
A salesperson earns $320 per week plus 8% of her weekly sales.
"8% of her weekly sales" means 
then;
the expression which represents her earning = 
"At least" means 
then;
the sales necessary for the salesperson to earn at least $1000 in the one week
⇒
Subtract 320 from both sides we have;

Divide both sides by 0.08 we get:

Therefore, the sales necessary for the salesperson to earn at least $1000 in the one week is: greater than or equal to $8500 i.e 
Hello,
x= the number
3x= three times the number
seven decreased by three times a number is forty, then:
7-3x=40
-3x=33
x=-11
Answer: the number is -11
Answer:

Step-by-step explanation:
It is known that,
<em>'Vertical stretch, stretches the function up and down towards the y-axis'.</em>
The general form of vertical stretch is given by 'kf(x)', where k>1 is the factor by which function is stretched.
As, we have the function
which is stretched by a factor of 4.
Thus, the new function will be
.
Hence, the equation for the vertical stretch is
.