Answer:
19. 4y+10
20. 15y²-6
21. 0.5x⁴+10.5
Step-by-step explanation:
The distributive property says the factor outside parentheses applies to each of the terms inside parentheses. Terms are collected in the usual way.
19. y + 4 + 3(y + 2) = y + 4 + 3y + 6 = 4y + 10
20. 3y² + 3(4y² -2) = 3y² + 12y² - 6 = 15y² - 6
21. 0.5(x⁴ - 3) + 12 = 0.5x⁴ - 1.5 + 12 = 0.5x⁴ + 10.5
