Question

solve 2x+5y=21000 and 5x+2y=21300

Answer 1

2x+5y=21000(1)
5x+2y=21300(2)
multiply 2) eq. with 5 and (1) eq. with 2
4x+10y=42000(3)
25x+10y=106500(4)
on subtracting (3)from(4)
21x=64500
x=64500/21
ans substituting the value of x in eq(1) we get
2*64500/21+5y=21000
y=31200/105