If y varies directly as x, find the unknown value in the problem below:

Mathematics

1 answer:

Oksi-84 [34.3K]2 years ago

3 0

12/-30=8x
cross multiply
12x=-240
x=-20

You might be interested in

I can't figure this out

andriy [413]

Suppose that equation of parabola is
y =ax² + bx + c

Since parabola passes through the point (2,−15) then
−15 = 4a + 2b + c

Since parabola passes through the point (-5,-29), then
−29 = 25a − 5b + c

Since parabola passes through the point (−3,−5), then
−5 = 9a − 3b + c

Thus, we obtained following system:
4a + 2b + c = −15
25a − 5b + c = −29
9a − 3b + c = −5

Solving it we get that
a = −2, b = −4, c = 1

Thus, equation of parabola is
y = −2x²− 4x + 1

____________________

Rewriting in the form of
(x - h)² = 4p(y - k)

i) -2x² - 4x + 1 = y

ii) -3x² - 7x = y - 11
(-3x² and -7x are isolated)

iii) -3x² - 7x - 49/36 = y - 1 - 49/36
(Adding -49/36 to both sides to get perfect square on LHS)

iv) -3(x² + 7/3x + 49/36) = y - 3
(Taking out -3 common from LHS)

v) -3(x + 7/6)² = y - 445/36

vi) (x + 7/6)² = -⅓(y - 445/36)
(Shifting -⅓ to RHS)

vii) (x + 1)² = 4(-1/12)(y - 445/36)
(Rewriting in the form of 4(-1/12) ; This is 4p)

So, after rewriting the equation would be -

(x + 7/6)² = 4(-⅛)(y - 445/36)

__________________

I hope this is what you wanted.

Regards,
Divyanka♪
__________________

6 0

2 years ago

Read 2 more answers

You make a large bowl of salad to share with your friends. Your brother eats 1/3 of it before they come over. You want to divide

shepuryov [24]

Divide 1/3 by 6 and there is your answer

6 0

3 years ago

Helphelphelphelphelp

Mkey [24]

Answer:1 7/8

Step-by-step explanation: 5 multiplied by 3 is 15 and 15/8 and since 8 goes into 15 once with 7 left over, the answer is 1 and 7/8