Question

Help me guys!!
Solve by the elimination method.
2x – 5y = 1
3x – 4y = -2

Answer 1

first you would isolate x in the first equation

Answer 2

1st add a*(eq1) to eq 2 in such a way that it makes the 3x component 0 x

Answer 3

3x+ a*2x=0
a*2x=-3x
a=-3x/2x xs cancels so a=-3/2
or if you can remember a is always -( x coefficient of eq1/ x coefficient of eq2 )

Answer 4

2x – 5y = 1
3x – 4y = -2

\/ -3/2 r1+r2

2x- 5y=1
0x-2/3y=-4/3

\/ now we must make y into 1
a*-2/3=1 -> the reciprocal -3/2 so multply r2 by it

2x- 5y=1
y =2


we now know y = 2 so we can back substitude into row 1

2x- 5(1)=1
2x-5=1
2x=6
x=3

so y=2 x=3

Answer 5

I got x=-2 and y=-1

Answer 6

oh then idk lol let me check on a calculator

Answer 7

you are right hmm. maybe i did an arithmetic error sorry.

Answer 8

steps are right tho

ax+by=c
dx+ey=f

get dx to equal 0 by adding some multiple of r1 to r2

ax+by=c
ab+ey=ac+f

get ab+ey to equal 1 by adding a multiple of r2
y=ac+f+a*somemultiple


y= ac+f+a*somemultiple = n
where n is some number you plug in n into first row and solve for x.