Verified answer

y - функция; x - аргумент

1. y(x) = 7 - 15x

y(6) = 7 - 15×6 = -83

y(0) = 7

y(-4) = 7 - 15×(-4) = 7 + 15×4 = 67

y(1/5) = 7 - 15×1/5 = 7 - 3 = 4

2. y = -4x + 15

0 = -4x + 15 <=> x = 15/4 = 3.75

-5 = -4x + 15 <=> x = 20/4 = 5

3 = -4x + 15 <=> x = 12/4 = 3

3. 3(2y + 7) - 4(y + 5) = 7 - (15y - 2)

6y + 21 - 4y - 20 = 7 - 15y + 2

2y + 1 = 9 - 15y

17y = 8

y = 8/17