evalaute the expression
Given 3x2 + 2x – y, evaluate when x = -5 and y = 7
The answer is - 47
This is how i did it:
3X2=multiple 3 x (-5) x 2= -15 x 2 = -30
2X-y = 2 x (-5) - 7= -10 - 7= -17
Add the two answers: -30 + (-17)= -47
I think what was meant is
3x^2 + 2x - y
3(25) + 2(-5) + 7 = 72
3(25) + 2(-5) - 7 = 58
To evaluate the expression 3x^2 + 2x - y when x = -5 and y = 7, follow these steps:
Step 1: Replace x with -5 and y with 7 in the expression.
3(-5)^2 + 2(-5) - 7
Step 2: Simplify the expression inside the parentheses.
3(25) - 10 - 7
Step 3: Perform the multiplication.
75 - 10 - 7
Step 4: Perform the subtraction.
75 - 17
Step 5: Calculate the final result.
58
Therefore, when x = -5 and y = 7, the value of the expression 3x^2 + 2x - y is 58.