I guess the chef is making the mixture for the sheriff... Let <em>x</em> be the amount of dressing with 5% vinegar that is required, and <em>y</em> the amount of 15% vinegar dressing (both amounts in mL).
The sheriff wants 390 mL of the mixed dressing, so that
<em>x</em> + <em>y</em> = 390
<em>x</em> mL of the 5% dressing contains 0.05<em>x</em> mL of vinegar, while <em>y</em> mL of the 15% dressing contains 0.15<em>y</em> mL of vinegar. The resulting mixture should have a concentration of 9% vinegar, so that it contains 0.09 (390 mL) = 35.1 mL of vinegar. This means
0.05<em>x</em> + 0.15<em>y</em> = 35.1
Solve for <em>x</em> and <em>y</em> :
<em>y</em> = 390 - <em>x</em>
0.05<em>x</em> + 0.15 (390 - <em>x</em>) = 35.1
0.05<em>x</em> + 58.5 - 0.15<em>x</em> = 35.1
23.4 = 0.10<em>x</em>
<em>x</em> = 234
<em>y</em> = 156
Absolute Value
Absolute Value
means ...
... only how far a number is from zero:
<span>
<span><span>
</span>
<span>
<span>
"6" is 6 away from zero,
and "−6" is also 6 away from zero.
So the absolute value of 6 is 6,
and the absolute value of −6 is also 6 </span>
</span>
</span></span>
More Examples:
<span><span>The absolute value of −9 is 9</span><span>The absolute value of 3 is 3</span><span>The absolute value of 0 is 0</span><span>The absolute value of −156 is 156</span></span>
No Negatives!
So in practice "absolute value" means to remove any negative
sign in front of a number, and to think of all numbers as positive (or
zero).
Absolute Value Symbol
To show that we want the absolute value of something, we put
"|" marks either side (they are called "bars" and are found on the right
side of a keyboard), like these examples:
<span>
<span><span>
|−5| = 5
|7| = 7
</span>
</span></span>
Sometimes absolute value is also written as "abs()", so abs(−1) = 1 is the same as <span>|−1| = 1</span>
Answer:
26 rows
Step-by-step explanation:
this is like a rectangle length×width situation.
seats per row = s
number of rows = r
s × r = 884
s = r + 8
so, we can use e.g. the second equation in the first :
(r + 8) × r = 884
r² + 8r = 884
r² + 8r - 884 = 0
the general solution to such a quadratic equation is
x = (-b ± sqrt(b² - 4ac))/(2a)
in our case
x = r
a = 1
b = 8
c = -884
r = (-8 ± sqrt(8² - 4×1×-884))/(2×1) =
= (-8 ± sqrt(64 + 3536))/2 = (-8 ± sqrt(3600))/2 =
= (-8 ± 60)/2 = -4 ± 30
r1 = -4 + 30 = 26
r2 = -4 - 30 = -34
a negative number did not make any sense for the number of rows, so r = 26 is our answer.
Answer:
0.+.20.=.40Step-by-step explanation:
