To evaluate the expression "3X + Y/Z + 2Y" using the given values of x, y, and z, you can follow these steps:
Step 1: Substitute the given values of x, y, and z into the expression.
3(-2.57) + 1.55 / (-1.98) + 2(1.55)
Step 2: Perform the calculations within parentheses.
-7.71 + 1.55 / (-1.98) + 3.1
Step 3: Perform the division.
-7.71 + 0.78 + 3.1
Step 4: Add the numbers.
-7.71 + 0.78 + 3.1 = -3.83
Step 5: Round the answer to the nearest tenth.
-3.8 (rounded to the nearest tenth)
Therefore, the value of the expression, when x = -2.57, y = 1.55, and z = -1.98, is approximately -3.8.