Here are the rest of the answers :
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6. The body mass index, I, can be used to determine an individuals risk for heart disease.
An index less than 25 indicates a low risk. The body mass index is given by the formula
I= 700w/H(squared), where w=weight in pounds and H=height in inches. Jerome is 77
inches tall. What weights will keep his body mass index between 22 and 31?
Jerome's body mass index will fall between 22 and 31 for the set of all weights such that
186.34___ <w<_262.57__
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7. Solve 2y+2y≤-16. What is the solution set?
Ans = y≤-4 , that is (-infinity, -4]
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8. Solve 4(8-2x)+2x<5(9+3x). Use set builder notation to describe the solution.
Simplifying ,we get 32-8x+2x < 45 +15x that is 21x> - 13 hence
{x| x> -13/21}
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9. Solve by elimination method
3x-9y=2
3x-9y=3
Substract equation (2) from (1) , we get 2=3 , so the Answer is NO Solution
What is the solution of the system?
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10. Two angles are complementary. The sum of the measure of the first angle and oneforth the second angle is 59.25º. Find the measure of the angles.
Let one angle be x , then other is 90-x (Complementary)
Also, given, x+(90-x)/4 = 59.25 so solving, we get 3x/4 = 59.25-22.5 = 36.75, so x = 49 degrees,
so other angle is 41 degrees
What is the measure of the smaller angle? 41 degrees
What is the measure of the other angle? 49 degrees
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11. Solve 3/8(7+2x)+3 is greater than or equal to 18
The solution set is?
3/8(7+2x)+3 >=18
That means 3/8(7+2x) >=15 that means 3(7+2x) >=120 , hence 6x>=99 hence x>=99/6
Hence x>=33/2 , hence x≥16.5 , hence [33/2, infinity)
12. Determine whether the ordered pair is a solution of the inequality (-3,4); 6x +y<-7
Ans put the pair in the equation, it satisfies, hence YES
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13. Solve the graph. 8x-11≤-4 or x-6≥8. The solution is? x≤____ or x≥____
Ans solution is x≤___7/8_ or x≥14____
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14. Solve x+6>4. The solution set is?
Ans x >-2 that is (-2, infinity)
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15. Graph the inequality on a plane 4x+5y≤20. All I need is the points.
Points are intercepts (5,0) and (0,4).
16. Solve by substitution method. 2x+3y=-3, -8x+y=51
Solution of the system is?
Substitute y = 51+8x in (1), we get
Ans = (-6,3) that is x=-6, y=3
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17. Solve by elimination method
6x+5y=-13
2x-5y=-11
Add the 2 equation we get =x= -3 and so y= 1 so (-3,1)
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18. 9<x<14. Solution in interval notation is ?
Ans = (9,14)
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19. Soybean meal is 18% protein;cornmeal is 9% protein. How many pounds of each
should be mixed together in order to get 360 lb mixture that is 15% protein? How many
point of cornmeal should be in the mixture?
Let soyabean be x pounds and cornmeal be y pounds, then we have x+y = 360 and 0.18x+0.09y
= 0.15(x+y) that is 0.03x = 0.06y that is x = 2y and hence solving we get x = 240 and y = 120lb
How many pounds of soybean should be in the mixture?
So , soyabean is 240gm
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20. Solve the system of equations by graphing, then classify
X+4=14
x-y=4.
What is the solution of the system? (10,6)
Is it consistant or inconsistent? Consistent
Are the equations dependent or independent? Independent