Answer:
17) 26
18) 66
19) 78
20) 145
Step-by-step explanation:
#17) 8 + 3n for n = 6
8 + 3*(6)
8 + 18 = 26
#18) (8 + 3)n for n = 6
(8 + 3)*6
(11)*6 = 66
#19) 90 - 4d for d = 3
90 - 4*(3)
90 - 12 = 78
#20) 7x + 2y for x = 15, y = 20
7*(15) + 2*(20) = 145
Answer:
x= - 4
Step-by-step explanation:
2 * x^2 + 8 * x = x^2 - 16
2 * x^2 - x^2 + 8 * x + 16 = 0
x^2 + 8 * x + 16 = 0
(x + 4) * (x + 4) = 0
x = - 4
The first step to solving this is to multiply both sides of the equation by 3
8 + 10y = 9y - 12
now move the variable to the left side and change its sign
8 + 10y - 9y = -12
move the constant to the right side and change its sign
10y - 9y = -12 - 8
collect the like terms for y
y = -12 - 8 (it equals 1 when you subtract 10 from 9 which is the same is simply saying "y")
calculate the difference on the other side of the equals sign
y = -20
this means that the correct answer to your question is -20.
let me know if you have any further questions
:)
