3 years ago

Solve the system by adding or subtracting -3x-3y=9 3x+8y=6

Mathematics

1 answer:

Montano1993 [528]3 years ago

5 0

Answer:

x = -6 y = 3

Step-by-step explanation:

Adding the two equations and you get, -3x-3y + 3x+8y= 6+9

=> 5y = 15

=> y = 3

Plug y in each equation

-3x -3(3) = 9

-3x -9 = 9

-3x = 18

x = -6

3x + 8(3) = 6

3x +24 = 6

3x = -18

x = -6

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(2x-3)(3x+4) expand and simplify

elixir [45]

Answer:

6x² - x - 12

Step-by-step explanation:

Each term in the second factor is multiplied by each term in the first factor.

(2x - 3)(3x + 4)

= 2x(3x + 4) - 3 (3x + 4) ← distribute both parenthesis

= 6x² + 8x - 9x - 12 ← collect like terms

= 6x² - x - 12 ← in expanded form

5 0

3 years ago

3x + y = 19 , and x + 3y = 1.<br> Find the value of 2x + 2y<br> Can anyone explain this one for me?

velikii [3]

$First\ solve\ system\ of\ equations\ to\ find\ values\ of\ x\ and\ y\\\\ \left \{ {{3x+y=19\ \ |*(-3)} \atop {x+3y=1\ \ \ \ \ \ \ \ \ }} \right.\\\\ \left \{ {{-9x-3y=-57} \atop {x+3y=1 }} \right.\\+------\\Addition\ method\\\\
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