1.

4x+y= -1 and 7x+y= -4 by elimination method.​

Answer»

ANSWER:

  • x = - 1
  • y = 4

GIVEN:

  • 4x + y = - 1

  • 7x + y = - 4

TO:

  • SOLVE by elimination method.

EXPLANATION:

  • 4x + y = - 1 ---------> 1

  • 7x + y = - 4 ----------> 2

Subtract the two equations

4x \:\:\:+\:\:\: y = \:\:\:- 1 \\ \\ \\ 7x\:\:\: + \:\:\:y = \:\:\:- 4 \\ \\ \\ ( - ) \: \: \: \: \: ( - ) \: \: \: \: \: \:\:( + )\\ \\ \underline{ \qquad\qquad\qquad\qquad\qquad} \\ \\ - 3x +\:\:0\:\:\:=\:\:\:3 \\ \\ \underline{ \qquad\qquad\qquad\qquad\qquad}

x = - 1

SUBSTITUTE x = - 1 in equation 1

4(-1) + y = - 1

- 4 + y = - 1

y = 3

VERIFICATION:

Substitute x = - 1 and in y = 3 equation 2

7(-1) + 3 = - 4

- 7 + 3 = - 4

- 4 = - 4

HENCE PROVED.


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