Hi there I having an Algebra Money Mixture Problem I can't figure out? Help!?

Question

Tom invested $11,000, part at 9% and part at 10% simple interest. How much money was invested at each interest rate if the total interest earned from both is $1050?

HI there how do I solve this and whats the answer, Is there a formula for this.

Answer 1

1050 = .09x + .1(11000 - x)

1050 = .09x + 1100 - .1x

-50 = -.01x

x = 5000

$5,000 @ 9%

$6,000 @ 10%