7 I think because if you would put a zero behind the 4 and 7 and add them together it will be 110 and all that's left if u subtract them from 180 is 70 (7)
Answer:
The value of r=
The value of x=
Step-by-step explanation:
Given that,
A) 
Now,

8(2r-2)=9(7r+10)
16r-16=63r+90
-16-90=63r-16r
-(16+90)=47r
-106=47r
r=
B) 
Now,

5(x+5)=9[3(x-2)-1]
5x+25=9[3x-6-1]
5x+25=9[3x-7]
5x+25=27x-63
25+63=27x+5x
83=32x
x=
As in each table can seat 8 people and the probability you need to find is about the first person you can ignore this data.
Probability that the first person to enter the room will be randomly seated at a maple table:

#maple tables: 9
# total tables: 9 +10 +5 +7=31

Then, the probability that the first person to enter the room will be randomly seated at a maple table is 9/31
You use the FOIL method, and how you do this is -
(x - 7) (x + 8)
Multiply the first x by both numbers in the second factor. Which means, you multiply x by x and 8, the two in (x + 8).
With this, you get -
x^2 + 8x
Then do the same thing with -7.
-7x - 56
Then combine the two.
x^2 + 8x - 7x - 56
Combine like terms.
x^2 + x - 56
So now, 7 x 8 is 56
And -7 + 8 would be 1. And that is the value of “x” which is b in the form a^2x + bx + c.
Now with this, you take those two numbers and make the factors =
(x + 8) (x - 7)
Then you set these equal to 0.
x + 8 = 0
Subtract the 8 from both sides.
x = -8
————
x - 7 = 0
Add the 7 on both sides.
x = 7
Answer: A
Lanzetta Elem. raised 5358....round to 5,000
Lantana Mid. Sch raised 2834....round to 3,000
Atlanta High Sch. raised 4132...round to 4,000
they need 14,000...they have (5,000 + 3,000 + 4,000) = 12,000....so they will need (14,000 - 12,000) = 2,000 more....keep in mind, these are estimates...not exact answers