Question

Substitution method. show work.7.) y=x+2 10.) 2x+y=3 y=3x+4 3x-y=2elimination method. show work.11.) 5x+y=9 12.) -7x+y=-19 10x-7y=18 -2+3y=-19

Answer 1

7) y= x+2

replacing this in the second equation we got:

x +2 = 3x +4

-2 = 2x

x= -1

And solving for y we got:

y = -1 +2 = 1

10) 2x +y = 3

If we solve for y we got:

y = 3-2x

And replacing into the second equation we got:

3x - 3+2x = 2

5x = 5

x= 1

And solving for y we got:

y = 3 -2*1 = 3-2= 1

11) If we multiply the first equation by -2 and we add to the second one we got:

-10 x -2y = -18

10x -7y = 18

___________

-9y = 0

y=0

x= (9-0)/5 = 9/5

12) If we multiply the first equation by -3 we got:

21x -3y = 57

-2x +3y =-19

_______________

19x = 38

x= 2

y= (-19 + 4)/3= -5