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3 years ago

Suppose y varies directly with x, and y= 7 when x = 3. What is the value of x when y = 28? If 7 = k(3) then 28 = k(x) Find x

1 answer:

7 0

Let y and x be the numbers that varies directly (that means they keep the same proportion)

Then we have 7y = 3x, OR y/x =7/3 (this ratio should be kept for any value of x and y:
y/x = 7/3, if y = 28, then 28/x = 7/3 or x = (3)(28)/7 = 12

SO X = 12

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All the factors of 48 are 1, 2, 3, 4, 6, 8, 12, 16, 24, and 48. True or False

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3 years ago

Read 2 more answers

What is the fourth term of the binomial expansion for (3x-2y)6

Thepotemich [5.8K]

One way is to just expand it by using binomial theorem
or to use pascal's triangle

ok so

to find the nth term of a binomial, (a-b). where the binomial is to the r power you do
n-1=k

rCk times $(a)^{r-k}(-b)^k$
and rCk= $\frac{r!}{k!(r-k)!}$

so

4th term
4-1=3
6 is exponent

6C3 $(3x)^{6-3}(-2y)^3$ =
$( \frac{6!}{3!(6-3)!} )((3x)^3(-8y^3)$ =
$( \frac{6*5*4}{1*2*3} )(27x^3)(-8y^3)$ =
$(20)(27)(-8)(x^3)(y^3)=-4320x^3y^3$

the 4th term is $-4320x^3y^3$

7 0

2 years ago

Solve the system of equations using any method. 2X – Y + Z = – 2, 6X + 3Y – 4Z = 8, – 3X + 2Y +3Z = – 6

krok68 [10]

Answer:

Z = - 2, Y = 0, X = 0

Step-by-step explanation:

2X – Y + Z = – 2

6X + 3Y – 4Z = 8

– 3X + 2Y +3Z = – 6

isolate "X" in the first equation

2X - Y + Z = - 2 => isolate "2X"

2X = - 2 - Z + Y => divide either side by 2

X = - 1 - Z/2 + Y/2

substitute this value of X in the second two equations (applying the substitution method here)

6(- 1 - Z/2 + Y/2) + 3Y - 4Z = 8,

6Y - 7Z - 6 = 8

- 3(- 1 - Z/2 + Y/2) + 2Y +3Z = - 6,

Y + 9Z + 6/2 = - 6

isolate Y in the second equation (6Y - 7Z - 6 = 8) and substitute in the third equation (Y + 9Z + 6/2 = - 6)

6Y - 7Z - 6 = 8 => isolate 6Y

6Y = 14 + 7Z => divide either side by 6

Y = 7Z + 14/6 => substitute in second equation

7Z + 14/6 + 9Z + 6/2 = - 6 => solve for Z

61Z + 50/12 = - 6, Z = - 2

substitute the value of Z into the equations "Y = 7Z + 14/6" and using the value of Y and Z, substitute into "X = - 1 - Z/2 + Y/2"

Y = (7(- 2) + 14)/6 = 0 / 6

= 0

X = - 1 - (- 2)/2 + 0/2 = - 1 - (-1) + 0

= - 1 + 1 + 0 = 0

6 0

2 years ago