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
I think the answer is 700 as 700*10=7,000.
A=8
B=10
Hope this helps :D
