solve the system of equations using the substitution method. 7x + y =1 and 3x + 2y = -9?

Answer 1

7x+y=1
y=1-7x ---(1)

3x+2y=-9 ---(2)

sub (1) into (2):

3x+2(1-7x)=-9
3x+2-14x=-9
-11x=-11
x=1

y=1-7x
y=-6

done.....thx to me

Answer 2

Rearrange the first equation 7x+y=1 by subtracting 7x from both sides. That gives you that y =1 -7x

Now substitute that value for y into the second equation. That gives you 3x+2(1-7x) = -9 which is -11x+2 = -9 or 11x = -1
Divide both sides by 11 and you get x=1 which is one part of the answer.
Now put that value for x into the first equation to get y=1-7(1)
or y= -6 which is the other part of the answer.

Answer 3

7x+y=1
y=(-7)x+1
y=(-7)(1)+1
y=(-7)+1
y= -6
------------------------
3x+2y=9
3x+2(-7x+1)=-9
3x-14x+2=-9
-11x=-11
x=1
-----------------
Answer: (1,-6)

Simply I singled out the y in the first equation and what y = I put in the place of y in the second equation and solved for x. The answer for x I then substituted back into the first equation to find y.

Answer 4

From the first equation y = 1-7x. Substitute this for y in the second and you get:
3x +2(1-7x) = -9, or -11x + 2 = -9, which means x=1. substitution of this value for x into either of the original equations yields a value of -6 for y.

Answer 5

By using subtitution method,
1.
Let y = 1 - 7x ;
3x + 2y = -9 ...........change y
3x + 2(1 - 7x) = -9
3x + 2 - 14x = -9
-11x = -9 - 2 ............move 2 to the right side, or -2 each side.
11x = 11 ........divide each side by -1 or change sign each side.
x = 1

Now that x = 1, y = 1 - 7(1) ; y = -6

2.
7x + y = 1 ; 7x = 1 - y ; x = (1 - y) / 7
3x + 2y = -9 ..................change x
3 [(1 - y) / 7] + 2y = -9
3/7 - 3y/7 + 2y = -9
(14y - 3y) / 7 = - (63 + 3) / 7
11y = -66
y = -6

Now that y = -6, 7x + (-6) = 1 ; 7x = 7 ; x = 1

Answer 6

7x + y = 1
3x + 2y = -9

7x + y = 1
y = -7x + 1

3x + 2(-7x + 1) = -9
3x + -14x + 2 = -9
-11x = -11
x = 1

y = -7(1) + 1 = -7 + 1 = -6

ANS : (1,-6)

Answer 7

7x+y=1
7x = 1-y
x=(1-y)/7

3x+2y =-9
3(1-y)+14y = -63
3-3y+14y = -63
11y = -66
y = -6

x = (1-(-6))/7 = 1

Answer 8

3x+2(1-7x)=-9
3x+2-14x=-9-11X=-11
x=1

y=1-7x
y=-6