algebra
posted by Az on .
find real numbers a and b if
a(3x+1)+b(5x1)=11x+9 for all x€r

you have
3ax + a + 5bx  b = 11x + 9
If these expressions are identical for all x, then like powers of x must be equal:
3a + 5b = 11
a  b = 9
so,
3(b+9) + 5b = 11
b = 2
a = 7