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
Michael worked 4.5 hours. 65.75 - 36.50 = 29.25, therefore, Michael made $29.25 not including tips. 29.25/6.50 = 4.5
Answer:
14. D
15. A
16. A
Step-by-step explanation:
14. Point slope form formula: y-y₁=m(x-x₁).
When graphing you always want to think x/y for your slope.
X-axis increases by 2 and the Y-axis increases by 10, which would make the slope (m) 2/10 = 1/5.
If your slope is does not come out correct, then you can prove your point.
15. The given information is (-2,2): m=-1.
Given the Point slope formula: y-y₁=m(x-x₁), you can replace m to -1, y₁=2 and x=+2. (Two negatives would make a positive.)
Your answer: y-2=-(x+2)
16. Given: y=4x-7; (3,0)
Parallels lines: Same slope different y-intercepts.
A and D has the same slope and different y-interecepts, but your answer would be A because the equation that was given as a negative y-intercepts.
You could convert them into improper fractions first. 7 7/8 should become 63/8 and 3 1/4 should become 13/4. Then, change both fractions so they share a common denominator. I'll use 8.
63/8-26/8 = 37/8, which is then converted into 4 5/8.
Hope that helped you.
