Question

Simplify the expression and find the value if y is equal to 3 y + 7 + 4 (y - 5)​

Answer 1

Answer: 21

Step-by-step explanation: Solve 3y(2y−7)−3(y−4)−63 for y=−2

First simplify it,

=6y  

2

−21y−3y+12−63

=6y  

2

−24y−51

Put y=−2

=6(−2)  

2

−24(−2)−51

=6×4+48−51

6×4+48−51

24+48−51

=21

Answer 2

Answer:

5xy(3x+4y−7)−3y(xy−x2+9)−8

= 15x

2

y+20xy

2

−35xy−3xy

2

+3x

2

y−21y−8

= 18x

2

y+17xy

2

−35xy−27y−8 When $$x

= 2, y -1,wehave=18(2)^2 x (-1) + 17(2) (-1)^2 - 35(2) (-1) - 27(-1) - 8$$

= 18×4×(−1)+17×2×1−35×2×(−1)−27×(−1)−8

= −74+34+70+27−8

= 131−80

= 51