## Thinking Mathematically (6th Edition)

Given -$x^{2}$ -4xy +3$y^{3}$, x=-1, y=-2 Step 1: Put the value of x=-1 and y=-2 for each x and y in the expression =-$(-1)^{2}$ -4(-1)(-2) +3$(-2)^{3}$ Step 2: Evaluate the exponential expression$(-1)^{2}$ = (-1)(-1) = 1 $(-2)^{3}$ = (-2)(-2)(-2) = -8 =-1-4(-1)(-2)+3(-8) Step 3: Multiply 4(-1)(-2) = 8, 3(-8) = -24 = -1-8-24 Step 4: Add and Subtract from left to right first add -1-8 -9-24 = -33