how do i do this

a.   3x   - 2y  = 14

     -2x  + 2y  = -10         just add the equations   and we have :

x  =  4         to find y......just substitute for x in either of the equations

3(4)  - 2y   = 14  

12  - 2y  =14        subtract 12 from both sides

-2y  = 2              divide both sides by -2

y = -1  

So......the solution is :  (x, y)   = ( 4, -1)

b.   y = 5x + 3

     -2x - 4y  = 10

Substitute the first equation for y into the second equation

-2x - 4[5x + 3]  = 10       simplify

-2x - 20x - 12  = 10

-22x  - 12  = 10      add 12 to both sides

-22x  = 22       divide both sides by -22

x = -1

And using y = 5x + 3,   we have that

y = 5(-1) + 3   = -2

So........the solution is   (x, y)   = ( -1, -2)

(a)       3x - 2y = 14  ------(1)

            -2x +2y = -10 ------ (2)

(1) + (2)

x = 4 ------(3)

Subst. (3) into (1)

3(4) - 2y = 14

3(4) - 14 = 2y

-2 = 2y

y = -1

Therefore x=4 and y= -1.

And I believe that is what your teacher will advise you to do.(Method of Elimination)

(b)    y = 5x+3 ------(1)

       -2x - 4y = 10 ------- (2)

Let's make (2) less complicated.

2x + 4y = -10

x + 2y = -5 ------ (3)

Looks better.

Your teacher may want you to do Method of Substitution......

so

Subst. (1) into (3),

x + 2(5x+3) = -5

x+10x+6 = -5

11x = -11

x = -1 ------ (4)

Subst (4) into (1)

y = 5(-1) + 3 = -5 +3 = -2

Therefore x=-1 and y=-2