The system is:
i) <span>2x – 3y – 2z = 4
ii) </span><span>x + 3y + 2z = –7
</span>iii) <span>–4x – 4y – 2z = 10
the last equation can be simplified, by dividing by -2,
thus we have:
</span>i) 2x – 3y – 2z = 4
ii) x + 3y + 2z = –7
iii) 2x +2y +z = -5
The procedure to solve the system is as follows:
first use any pairs of 2 equations (for example i and ii, i and iii) and equalize them by using one of the variables:
i) 2x – 3y – 2z = 4
iii) 2x +2y +z = -5
2x can be written as 3y+2z+4 from the first equation, and -2y-z-5 from the third equation.
Equalize:
3y+2z+4=-2y-z-5, group common terms:
5y+3z=-9
similarly, using i and ii, eliminate x:
i) 2x – 3y – 2z = 4
ii) x + 3y + 2z = –7
multiply the second equation by 2:
i) 2x – 3y – 2z = 4
ii) 2x + 6y + 4z = –14
thus 2x=3y+2z+4 from i and 2x=-6y-4z-14 from ii:
3y+2z+4=-6y-4z-14
9y+6z=-18
So we get 2 equations with variables y and z:
a) 5y+3z=-9
b) 9y+6z=-18
now the aim of the method is clear: We eliminate one of the variables, creating a system of 2 linear equations with 2 variables, which we can solve by any of the standard methods.
Let's use elimination method, multiply the equation a by -2:
a) -10y-6z=18
b) 9y+6z=-18
------------------------ add the equations:
-10y+9y-6z+6z=18-18
-y=0
y=0,
thus :
9y+6z=-18
0+6z=-18
z=-3
Finally to find x, use any of the equations i, ii or iii:
<span>2x – 3y – 2z = 4
</span>
<span>2x – 3*0 – 2(-3) = 4
2x+6=4
2x=-2
x=-1
Solution: (x, y, z) = (-1, 0, -3 )
Remark: it is always a good attitude to check the answer, because often calculations mistakes can be made:
check by substituting x=-1, y=0, z=-3 in each of the 3 equations and see that for these numbers the equalities hold.</span>
Step-by-step explanation:
Most accurate one would be how many pounds he bought. Occasionally, the number he bought could also be used
Answer:
89 hours
Step-by-step explanation:
First solve all the deductions.
For each multiply the $10, which you are paid, and the percentage.
For FICA: $10 x 0.0765 = $0.77 per hr
For Fed tax: $10 x 0.12 = $1.2 per hr
For State tax: $10 x 0.08 = $0.8 per hr
Now subtract the remaining pay:
10 – 0.77 – 1.2 – 0.8 = $7.23
Time required = $640 / $7.23 per hr
Time required = 89 hrs
Final answer:
89 hours
Answer:
D
Step-by-step explanation:
D represents absolute value, and this is what you use to find the answer to this equation.
Answer:
i cannot help you get the answer to the question without more information but i can explain how to solve it, what your question is, is called a "permutation"
Step-by-step explanation:
To calculate permutations, use the equation nPr, where n is the total number of choices and r is the amount of items being selected. To solve this equation, use the equation nPr = n! / (n - r)! , an exclimation point means the factorial, say we need the factorial of 4, we would do this 4x3x2x1 go left to right, and it is not all at once. you multiply 4 times 3 which equals 12, then multiply 12 times 2... so on and so forth
