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>
I can’t answer because I don’t have the picture of the triangle
3x(2) + 2(2x - 20) = 16 - 2x(2)
6x + 4x - 40 = 16 - 4x
10x - 40 = 16 - 4x
14x - 40 = 16
14x = 56
x = 4
Hope this helps! ;)
This is the concept of area of solid materials, we are required to calculate the total area of horsehide that is required to cover 100 balls with each having a circumference of 9 in.
The area of hide required will be given by:
area=(area of each ball)*(total number of balls)
area of each ball is given by:
SA=4πr^2
given that the circumference is 9in, we are required to find the radius of the ball
Circumference, c=2πr
thus;
9=2πr
r=9/(2π)
r=1.4 in
Therefore the surface area will be:
SA=4π*1.4^2=24.6 in^2
Therefore the area of horsehide required to cover 100 balls will be:
Area=24.6*100=2,460 in^2.
We hope to answer more of your questions and inquiries soon. Have a nice day ahead! :)
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