Money is invested in two accounts, twice as much in one paying 3% interest per year as in the other, which pays 4% interest per year. The total interest earned after one year is $140. If x is the amount invested at the 3% rate
and the y is the amount invested at the 4% rate, then write a system of equations that will have a solution that
gives the amount invested at each rate, and find the x and y?

a reflection across the x-axis , followed by the by a reflection across the y-axis , and then a scale dilation of 0.5 .

you are playing an adventure game on your computer. you come across a troll who won't let you pass and there is no other way to get to the other side of the river except over the bridge he is guarding.

the troll is a nerd. he takes great delight in watching people struggle with his problems. very few get them. he only gives you one chance and then he changes the puzzle. you have to solve this one.

before you are four blocks. they are numbered 11,6, -7,21.

he tells that the answer he wants is minus and between -1 and - 2. you can use +, -, ×, ÷   ( and ) as many times as you like or no times at all. you don't like the way he's looking at you, but you need to cross the bridge. what do you do?