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Alex_Xolod [135]
2 years ago
8

2x-3y=7 and y=3x-7 how do you solve this using subsitution

Mathematics
1 answer:
adell [148]2 years ago
4 0

2x-3y = 7~~~....(i)\\\\y = 3x -7~~~....(ii)\\\\\\\text{Substitute}~ y = 3x -7~ \text{in equation (i):}\\\\\\2x-3(3x-7) = 7\\\\\implies 2x -9x + 21 =7\\\\\implies  -7x = 7 -21\\\\\implies -7x = -14\\\\\implies x = \dfrac{-14}{-7} = 2\\\\\\\text{Substitute x = 2 in equation (ii):}\\\\y=3(2) -7 = 6 -7 = -1\\\\\\\text{Hence (x,y) =(2,-1)}

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How much time Eight can you go into 400 and how much time 5 in going to 64 and how much time 4 can going into to 78
Ann [662]

Answer:

Step-by-step explanation:

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64/5=12.8

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8 0
3 years ago
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
3 years ago
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Answer:

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8 0
3 years ago
What is the function rule for the graph below?
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Y= -x^2+4

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