1. Evaluate a + b if a = 7 and b = 3. a + b = 2. Evaluate a - b if a = 8 and b = 2. a - b = 3. Evaluate ab if a = 3 and b = -5. ab = 4. Evaluate 2a + b if a = 4 and b = -8. 2a + b = 5. Evaluate abc if a = 4, b = 5 and c = 2. abc = 6. Evaluate 4yz - 5 if y = 2 and z = 10. 4yz - 5 = 7. Evaluate y - z if y = -2 and z = -6. y - z = 8. Evaluate -a - b - ab if a = -3 and b = -4. -a - b - ab= 9. Evaluate -x - (-a + b) if x = 2, a = -4 and b = -6. -x - (-a + b) = 10. Evaluate mx + b if m = -2, x = 4 and b = -3. mx + b = 11. Evaluate -(m + x)(-a + mx) if m = 2, x = -3 and a = -4. -(m + x)(-a + mx) = 12. Evaluate -xa(x - a) + a if x = 4 and a = -2. -xa(x - a) + a = 13. Evaluate x - xy if x = -2 and y = 3. x - xy = 14. Evaluate a - (ab - a) if a = -4 and b = -2. a - (ab - a) = 15. Evaluate x - ab(a - b) if x = -3, a = -2 and b = -4. x - ab(a - b) = 16. Evaluate -xa(a + x) + x if x = -4 and a = -2. -xa(a + x) + x = 17. Evaluate xm - 2m if x = -2 and m = -3. xm - 2m = 18. Evaluate 2abc - 3ab if a = 2, b = -3 and c = 4. 2abc - 3ab = 19. Evaluate a2 - b if a = 4 and b = -8. a2 - b = 20. Evaluate a2 + b2 if a = -3 and b = -7. a2 + b2 = |