So we can put in to a fraction and times both values by ten then we can divide as shown
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
Please provide the formula for me to answer
−
x^
2
+
10
x
+
7 so the answer is B.
hope it helps
Answer:
The dimensions of the screen are
Length:102 feet
Width: 82 feet
Step-by-step explanation:
we know that
The area of the rectangle (movie screen) is equal to
where
L is the length
W is the width
we have
so
----> equation A
The screen is 20 feet longer than it is wide.
so
---> equation B
substitute equation B in equation A
solve for W
solve the quadratic equation by graphing
the solution is W=82 ft
see the attached figure
Find the value of L
therefore
The dimensions of the screen are
Length:102 feet
Width: 82 feet
