Answer:
4y - yx(3-7y) + 5 + 2(8-y) equals to 7xy^2  − 3xy  +  2y  +  21
Step-by-step explanation:
1. Multiply numbers inside the parentheses.
4y - yx(3-7y) + 5 + 2(8-y)= 4y  −  3yx  + 7y^2x  +  5  +  16  −  2y
2. Then combine all like terms
4y  −  3yx  + 7y^2x  +  5  +  16  −  2y
4y - 2y = 2y
2y  −  3yx  +  7y^2x  +  5  +  16
5 + 16 = 21
2y  −  3yx  +  7y^2x  +  21
3. After combining like terms, simplify.
2y  −  3yx  +  7y^2x  +  21
Move y^2
2y  −  3yx  +  7xy^2  +  21
Move 2y
−  3yx  +  7xy^2  + 2y +  21
Reorder - 3yx and 7xy^2 (7xy^2 is more bigger than -3yx)
7xy^2  −  3yx  + 2y +  21
4. Final answer = 7xy^2  − 3xy  +  2y  +  21