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