16m^4 - n^4
= (4m^2 + n^2)(4m^2 - n^2)
= (4m^2 + n^2) (2m + n)(2m - n)
Answer: D
<u>Step-by-step explanation:</u>
Let x represent the score on her next test
78 + 92 + 88 + 89 + x = 5(90)
347 + x = 450
<u> -347 </u> <u>-347 </u>
x = 103
Answer:
546 ft³
Step-by-step explanation:
In the figure attached, the top view of the pool is shown. It can be decomposed into a trapezoid which height is 12 ft and which bases are 9 ft and 11 ft; and a rectangle which height is 1.5 ft and and it base is 11 ft.
Area of the trapezoid: (9 + 11)/2 * 12 = 120 ft²
Area of the rectangle: 1.5*11 = 16.5 ft²
Total area: 120 + 16.5 = 136.5 ft²
Volume of the pool: Total area * deep = 136.5 * 4 = 546 ft³
Answer:76.9 pounds
Step-by-step explanation: you subtract 5.5 pounds from the 82.4 pounds to get your answer
Answer:
Wyzant
ALGEBRA WORD PROBLEM
Dorian S. asked • 06/28/17
THREE LINEAR EQUATIONS WITH THREE VARIABLES
A chemist has three different acid solutions. The first acid solution contains 15% acid, the second contains 25%,
and the third contains 70%. He wants to use all three solutions to obtain a mixture of 40 liters containing 45%
acid, using 2 times as much of the 70% solution as the 25% solution. How many liters of each solution should be used?
How to set up as three linear equations to find the answer?
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1 Expert Answer
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Arthur D. answered • 06/28/17
TUTOR 4.9 (67)
Forty Year Educator: Classroom, Summer School, Substitute, Tutor
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set up 2 equations
the first equation...
15%*x+25%*y+70%*2y=45%*40
0.15x+0.25y+1.4y=0.45*40
0.15x+1.65y=18
multiply all terms by 100
15x+165y=1800
divide all terms by 15
x+11y=120
the second equation...
x+y+2y=40
x+3y=40
x=40-3y
substitute into the first equation x+11y=120
40-3y+11y=120
40+8y=120
8y=120-40
8y=80
y=80/8
y=10 liters
x+3*10=40
x+30=40
x=40-30
x=10 liters
10 liters of 15%, 10 liters of 25%, and 20 liters of 70%
check:
10*15%=1.5
10*25%=2.5
20*70%=14
1.5+2.5+14=18
18/40=9/20=45/100=45%
45%*40=18
hope it helps
please mark brainliest
