Can anyone help me in this with work pls i will mark u as brainiest
1) 9x+4y=11
3x-10y=-2
2) 4x+3y=21
5x+2y=21

Respuesta :

1) 9x+4y=11

3x-10y=-2 -----> 9x-30y=-6

   9x+4y=11

-(9x-30y=-6)

------------------

34y=17

y=1/2

9x+4(1/2)=11

9x=9

x=1

2) 4x+3y=21 -----> 8x+6y=42

5x+2y=21 -----> 15x+6y=63

  8x+6y=42

-(15x+6y=63)

-7x=-21

x=3

4(3)+3y=21

3y=9

y=3

Answer:

1) x=1 and y=1/2

2) x=3 and y=3

Step-by-step explanation:

1) 9x+4y=11;3x−10y=−2

Step: Solve9x+4y=11for x:

9x+4y=11

9x+4y+−4y=11+−4y(Add -4y to both sides)

9x=−4y+11

9x/9= −4y+11/9

(Divide both sides by 9)

x= −4/9y + 11/9

Step: Substitute

−4/9y + 11/9 for x in 3x−10y=−2:

3x−10y=−2

3(−4/9y + 11/9)−10y=−2

−34/3y + 11/3 =−2(Simplify both sides of the equation)

−34/3y + 11/3 + −11/3 = −2+ −11/3 (Add (-11)/3 to both sides)

-34/3y = -17/3

-34/3y             -17/3

----------    =     ---------       ( Divide both sides by ( -34)/3 )

-34/3              -34/3

Step: Substitute 1/2 for y in x= -4/9y + 11/9

x= -4/9 + 11/9

x= -4/9 ( 1/2) + 11/9

x=1 ( Simplify both sides of the equation)

Answer:

x= 1 , y= 1/2

2) 4x+3y=21 ; 5x+2y=21

Step: Solve4x+3y=21for x:

4x+3y=21

4x+3y+−3y=21+−3y(Add -3y to both sides)

4x=−3y+21

4x

4

=

−3y+21

4

(Divide both sides by 4)

x=

−3

4

y+

21

4

Step: Substitute

−3

4

y+

21

4

forxin5x+2y=21:

5x+2y=21

5(

−3

4

y+

21

4

)+2y=21

−7

4

y+

105

4

=21(Simplify both sides of the equation)

−7

4

y+

105

4

+

−105

4

=21+

−105

4

(Add (-105)/4 to both sides)

−7

4

y=

−21

4

−7

4

y

−7

4

=

−21

4

−7

4

(Divide both sides by (-7)/4)

y=3

Step: Substitute3foryinx=

−3

4

y+

21

4

:

x=

−3

4

y+

21

4

x=

−3

4

(3)+

21

4

x=3(Simplify both sides of the equation)

Answer:

x=3 and y=3

Hope this really helped! Pls mark brainliest thx :)

ACCESS MORE