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gulaghasi [49]
3 years ago
9

Y = 7x + 20 4x - y = -11 solve by substitution

Mathematics
2 answers:
fiasKO [112]3 years ago
8 0

Answer:

  • x = -3
  • y = -1

Explanation:

y = 7x + 20 __ equation 1

4x - y = -11

y = 11 + 4x __ equation 2

<u>using substitution method,</u>

11 + 4x = 7x + 20

4x - 7x = 20 - 11

-3x = 9

x = -3

Find y,

y = 7x + 20

y = 7(-3) + 20

y = -1

GuDViN [60]3 years ago
5 0

Answer:

x = - 3, y = - 1

Step-by-step explanation:

y = 7x + 20 -----> equation 1

4x - y = - 11

4x - ( 7x + 20 ) = - 11

4x - 7x - 20 = - 11

- 3x = - 11 + 20

- 3x = 9

x = 9 / - 3

x = - 3

Substitute x = - 3 in equation 1,

y = 7 ( - 3 ) + 20

  = - 21 + 20

y = - 1

Hence,

x = - 3

y = - 1

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