Answer: The value of y is 39.6 when x = 11 and the required expression is y(11) = 39.6
Step-by-step explanation:
Since we have given that
y varies directly as x.
If y = 18, when x = 5.
So, we need to find the value of y when x is 11.
According to question, we get that
Hence, the value of y is 39.6 when x = 11 and the required expression is y(11) = 39.6
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:
The general equation following the pattern becomes is 7 + (n - 1)×2
Where, n = The figure number - 1
Step-by-step explanation:
The pattern in the question can be described as follows;
Figure 2 = (5 + 2) squares boxes = 7 squares boxes
Figure 3 = (5 + 2 + 2) squares boxes
Figure 4 = (5 + 2 + 2 + 2) squares boxes
Therefore, the number of squares boxes per figure, form an arithmetic progression (a + (n - 1)d) with the first term a = 7, the common difference d = 2, and the n = the nth term of the series, such that the general equation following the pattern becomes;
7 + (n - 1)×2.
Well, i'm just going to take a stab at this:
The answer out of:
> It is (18,9) ,
> It is (9, 18)
I believe both are correct as those are both plausible coordinates (although I may be wrong)
Line R: 2x + 2y = 18 (x + y = 9)
Line M: x + y = 9
There are infinite many solutions as they are the same line.
Answer:
x=3; y=5
Step-by-step explanation:
y=x+2
y=3x-4
so x+2=3x-4
2x=6
x=3
because y=x+2
x=3
so y=3+2
=5
