Final answer:
Mina saved 3/5 more than Zach, which translates to the equation y = x + 0.6x or y = 1.6x. Therefore, the correct answer is y = 1.6x.
Step-by-step explanation:
Zach saved x dollars over the last year, and Mina saved rac{3}{5} more than Zach did. To find out how much money Mina saved, we add three-fifths of the amount Zach saved to Zach's total savings. This can be expressed as the equation:
Mina's savings (y) = Zach's savings (x) + rac{3}{5} × Zach's savings (x)
Combining the terms for Zach's savings, we get:
y = x + 0.6x = 1.6x
Therefore, the correct equation to represent how much money Mina saved is y = 1.6x, which is choice (d).