Answer:
perimeter of a children's playground, area of a house, volume of a glass of orange juice.
Step-by-step explanation:
Answer: $638.40
Step-by-step explanation:
45% converted to a decimal is 0.45
0.45 of $1200 = 0.45* $1200 (of in this case means multiply)
0.45 * $1200= $440
Because they said 11% of remaining salary, we have to do:
$1200-$440=$760
Now 11% converted to a decimal is 0.11
5% converted to a decimal is 0.05
So 0.11+0.05
0.11+0.05= 0.16
Now 0.16 *$760=$121.60
Now we find the remaining amount so we subtract: $760-$121.60= $638.40
So our answer is $638.40 left
15/x = 5/11
5x = 165
x = 33
OK. These problems are easy if you know the quadratic formula,
and they're impossible if you don't.
Here's the quadratic formula:
When the equation is in the form of Ax² + Bx + C = 0
then x = [ -B plus or minus √(B²-4AC) ] / 2A
I'm sure that formula is in your text or your study notes,
right before these questions. You should cut it out or
copy it, and tape it inside the cover of your notebook.
Then, you'll always have it when you need it, until
you have it memorized and can rattle it off.
The first question says 3x² + 5x + 2 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes ! A=3 B=5 C=2
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
= [ -5 plus or minus √(5² - 4·3·2) ] / 2·3
= [ -5 plus or minus √(25 - 24) ] / 6
= [ -5 plus or minus √1 ] / 6
x = -4 / 6 = -2/3
and
x = -6 / 6 = -1 .
_______________________________________
The second question says
4x² + 5x - 1 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes it is ! A=4 B=5 C= -1
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
Now, you take it from here.
Answer:
for four copies the cost is $72
Step-by-step explanation:
52 + 5a = 24 + 12a
28 + 5a = 12a
28 = 7a
a = 4
52 + 20 = 72
for four copies the cost is $72
