7n^2 + 5 = 453
Subtract 5 from both sides:
7n^2 = 448
Divide both sides by 7:
N^2 = 64
Take the square root of both sides:
N = 8
Answer:
noted, thanks for the note
A) 4(25-3y)+5y=9
100-7y=9
91=7y
y=13
(-14,13)
b) 14-x=x-10
2x=24
x=12
(12,14)
c) 4x=12
(3,7)
d) 18.5x+10.4y=200
x+y=130
Jenny won the race as she finished the race much more quickly and has greater average speed than Lester.

Jenny: distance/time = 100/15.2 = 6.58 m/s = 6.6 m/s
Lester: distance/time = 100/15.7 = 6.37 m/s = 6.4 m/s
6x-9=15
6x=24
x=4
Therefore the answer is A.
Hope this helps :)