Solve the system of equations. -10y+9x=-9
10y+5x=-5

by the use of elimination method

make all coefficients of subject to be eliminated similar..by multiplying the coefficients with one another

for eqn(i)

5(-10y+9x=-9)

-50y+45x=-45

for eqn(ii)

9(10y+5x=-5)

90y+45x=-45

-50y+45x=-45

90y+45x=-45

...subtract each set from the other...

we get

-140y+0=0

y=0

from eqn(i)

10y+5x=-5

0+5x=-5

x= -1