a) 7a-20 = 7*(-6) - 20 = -42-20 = -62
b) 50-3x = 50-3*9 = 50-27 = 23
c) 10m+m² = 10*2+2² = 20+4 = 24
d) w²-4w = (-5)²-4*(-5) = 25+20 = 45
e) 2z²+3z = 2*1²+3*1 = 2*1+3 = 2+3 = 5
f) 4t-2 = 4 * [tex]\frac{1}{2}[/tex] -2 = 2-2 = 0
