Part of a $3,600 bonus was invested at 9% annual simple interest. The rest was invested at %8 annual simple interest. The total interest at the end of one year was $312. How much was invested in the %9 account?

  $2400

Step-by-step explanation:

Let x represent the amount invested at 9%. (3600-x) will be the amount invested at 8%. The total interest earned is then ...

  312 = 0.09x +0.08(3600 -x)

  24 = .01x . . . . subtract 288, simplify

  2400 = x . . . . divide by .01

$2400 was invested in the 9% account.

180-142=38 for the acute angle next to the entry

90+38=128

180-128=52

a=52

step-by-step explanation: