I'll assume the above equation is: 9 - 7x = 7 - 4(2x+3)
* do distributive multiplication
9 - 7x = 7 - 8x - 12
*move like terms
-7x + 8x = 7 - 12 - 9
* solve for x
x = 7 - 21
x = -14
To check, substitute x by its value -14
9 - 7x = 7 - 4(2x+3)
9 - 7(-14) = 7 -4[2(-14) + 3]
9 + 98 = 7 - 4(-28 +3)
107 = 7 - 4(-25)
107 = 7 + 100
107 = 107
Area=3.14(r)^2
radius is half of diameter
3.14(9.5)^2=283.385
rounded is 283.39
It’s D, because the x-value, 8, has two y-values, the 5 and 9. In order to be a function, each x-value has to have only one y-value.
I think it’s B) 30 degrees
After the first day, 1/3 of the original amount remained:
... (1/3)·45 = 15
After the second day, 2/3 of that amount remained:
... (2/3)·15 = 10
The bookstore has 10 copies left.