If x = 5, y = -3. evalue 3x-2y
Thus, substitute x = 5 and y = -3
3(5)-2(-3) = 15-(-6) = 15+6 = 21 #
Simplify 6x-20y+7z-8x+25y-11z
Subtraction and Addition, just subtract and addition of polynomial. Same variable subtract/addition with same variable.
Thus, (6x-8x)+(-20y+25y)+(7z-11z) = -2x+5y-4z #
