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>
Answer:
it is not a good estimate.
Step-by-step explanation:3816 can be rounded to 4000 and 467 can be rounded to 500. Adding 4000+500 gives 4500, which isn't near 8000.
i hoped this helped :)
<3
Answer:
x=17
Step-by-step explanation:
ok so since lines PR and RQ are congruent (we know because of the lines on them), that means angles P and Q are also equal.
now we can set up the equation to find x like this:
29+29+(8x-14)=180 (180 because the three angles of a triangle always equal 180)
x=17
Answer:
Step-by-step explanation:
on the edge of a cliff overlooking the Pacific ocean. You see a sailboat down in the water below you. The angle of depression to the sailboat is 28◦ . A quick tells you that the cliff you’re standing on is 150ft. How far away from the boat are you, in feet, rounded to one decimal place?(30pts)
We solve using the Trigonometric function of TANGENT
tan 28 = 150/x
7. Answer is D! 1 to the 3rd power, 1^3, or 1 cubed as you'll hear it, is 1 because when something is cubed that means it's times itself 3 times. (EX: 4^3 = 4x4x4) 2 cubed is 8. 3 cubed is 27. 4 cubed is 64 and 5 cubed is 125!
8. Answer is C! A is gaining speed and B is the capped speed, meaning it can't get any higher, and C is the loss of speed.
