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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Arthur D. answered • 06/28/17
TUTOR 4.9 (67)
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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
Answer:
3rd option
Step-by-step explanation:
8 - 3x ≥ - 4 ( subtract 8 from both sides )
- 3x ≥ - 12
divide both sides by - 3 , reversing the symbol as a result of dividing by a negative quantity.
x ≤ 4
since ≤ the circle on number line is solid ( not open )
since less than 4 then arrow points left away from 4
the solution is shown on the third graph
Answer:
She wrapped 5 presents
Step-by-step explanation:
She used 2cm to wrap each present
8cm = 4x
x is the amount of presents
divide by 4
x= 2 cm
Given 10 cm, divide by 2 to determine amount of x, or presents
Graham: -50x + 14,040
Max: 20x + 12,500
Graham = Max
-50x + 14,040 = 20x + 12,500
<u>+50x </u> <u>+50x </u>
14,040 = 70x + 12,500
<u> -12,500 </u> <u> -12.500 </u>
1,540 = 70x

220 = x
Answer: 220 minutes <em>(3 hours 40 minutes)</em>