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Natasha2012 [34]
3 years ago
10

4x - 9y = -21 - 4x – 3y = 9

Mathematics
1 answer:
lapo4ka [179]3 years ago
5 0

Answer:

(-3,1)

y= 1

x= -3

Step-by-step explanation:

4x-9y=-21

-4x-3y=9

solve the equation

4x=-21+9y

-4x-3y=9

substitute the value of 4x onto an equation

-1(-21+9y)-3y=9

multiply -1 to the numbers in parenthesis

-21+-9-3y=9

add -9 to 9 and put the negative on nine as a positive.

-21-3y=18

add -21 to 18 but since 21 is a negative the equation is subtraction.

-3y=-3

divide Both sides by -3

y=1

substitute the value of y into an equation

-4x-3•1=9

multiply 3 to 1

-4x-3=9

put -3 as a positive and add 3 to 9

-4x=12

divide both sides by -4

x= -3

(-3,1)

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