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2 years ago

Solve the simultaneous equations 4x + 5y = 4 2x - y = 9 Show clear algebraic working.

Mathematics

2 answers:

Natasha2012 [34]2 years ago

7 0

Step-by-step explanation:

4x+5y=4 (equation 1)

2x-y=9 (equation2)

solving equation 1 and 2 and multiplying equation 2 by 2

4x+5y=4

4x-2y=18

- + -

________

7y= -14

y= -2

putting the value of y in equation 2

2x-y=9

2x+2=9

2x=7

x=3.5

Mashcka [7]2 years ago

7 0

Answer:

$x= \dfrac 72, ~~y= -2$

Step by step explanation:

$4x+5y=4~~~...(i)\\\\2x-y=9~~~...(ii)\\\\\text{Multiply eq (ii) by 2 to isolate x:}\\\\4x-2y=18~~~.....(iii)\\\\(iii)-(i):\\\\4x-2y-4x-5y=18-4\\\\\implies -7y=14\\\\\implies y = -\dfrac{14}7 = -2\\\\\text{Substitute}~ y=-2~ \text{in equation (iii):}\\\\4x-2(-2) = 18\\\\\implies 4x +4 = 18\\\\\implies 4x = 18-4\\\\\implies 4x = 14\\\\\implies x = \dfrac{14}4 = \dfrac 72\\\\\text{Hence}~ (x,y) =\left(\dfrac 72 , -2 \right)$

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Step-by-step explanation:

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3 years ago

How to write (8x100,000)+4x1,000)+(6x1) in word form

BARSIC [14]

Answer:

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Step-by-step explanation:

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3 years ago

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goblinko [34]

Answer:

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Step-by-step explanation:

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Please Mark as Brainliest.

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Answer:

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3 years ago

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daser333 [38]

Answer:

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Step-by-step explanation:

Step 1: Combine like terms

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$3x - 7y$

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3 years ago

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