Question

Help please!! Much appreciated!

Solve each system by any method of your choice:

2x-5y=-1
4x-5y=-7

Answer 1

some say elimination is easiest

Answer 2

you can exchange rows

4x-5y=-7 add -1*r2 into r1
2x-5y=-1

Answer 3

So then the 5's would cancel out?

Answer 4

i mean -2 times r2 into r1

Answer 5

you could also do that too C but i rather start from the outer left most variable.

Answer 6

4x-5y=-7 add 1*r2 into r1
2x-5y=-1

6x=-8
2x-5y=-1

Answer 7

Oh my gosh, I am so sorry, my computer shut down on me! haha(: Thank you!

Answer 8

6x=-8
2x-5y=-1

from here you know x=-8/6=-4/3 and you can plug that into the bottom equation

2(-4/3)-5y=-1 and solve for y

Answer 9

i think it looks wrong let me do it again.

Answer 10

2x-5y=-1
4x-5y=-7

add -1r2 to r1

-2x = 6
4x-5y=-7

I see now so

-2x=6 is x=-3

now plug that into second equations
4x-5y=-7

4*-3-5y=-7

Answer 11

-12-5y=-7
-5y=5
y=-1

Answer 12

Haha(: Thank you so much! Much appreciated!! GBU!! :)

Answer 13

2x - 5y = -1 -->(-1)2x - 5y = - 1
4x - 5y = - 7
---------------
-2x + 5y = 1 (result of multiplying by -1)
4x - 5y = - 7
----------------add
2x = -6
x = 6/-2
x = -3
now sub -3 in for x in either of the equations
4x - 5y = - 7
4(-3) - 5y = - 7
-12 - 5y = - 7
-12 + 7 = 5y
- 5 = 5y
-5/5 = y
-1 = y
check...
2x - 5y = - 1
2(-3) - 5(-1) = - 1
-6 + 5 = - 1
-1 = -1 (correct)
ANSWER : x = - 3, y = -1 or (-3,-1)

Answer 14

Wow! haha(: Thanks so much! Such a bug help!! GBU!!

Answer 15

*big :P