Let's say the amounts are "a" and "b"
6% 4%
now... we dunno what "a" is, but nevermind, whatever that is, "b" invested at 4%, is 1600 less than that or less than "a", namely b = a - 1600
so.. "a" is the bigger amount than "b" by 1600, but no matter
what is 6% of a? well, 6/100 * a or 0.06a, that's how much it yielded
what is 4% of b? well, 4/100 * b, or 0.04b, that's much it earned in interests
we know, their yield, or total in earned interest is 156, so.. whatever those yields are, they add up to 156 or
0.06a + 0.04b = 156
now
solve for "a", to see how much was invested at 6%
how much is "b"? well, b = a - 1600
6% 4%
now... we dunno what "a" is, but nevermind, whatever that is, "b" invested at 4%, is 1600 less than that or less than "a", namely b = a - 1600
so.. "a" is the bigger amount than "b" by 1600, but no matter
what is 6% of a? well, 6/100 * a or 0.06a, that's how much it yielded
what is 4% of b? well, 4/100 * b, or 0.04b, that's much it earned in interests
we know, their yield, or total in earned interest is 156, so.. whatever those yields are, they add up to 156 or
0.06a + 0.04b = 156
now
solve for "a", to see how much was invested at 6%
how much is "b"? well, b = a - 1600