Answer:
12
Step-by-step explanation:
Let d represent the number of dimes Lily saved. Then the value of her coins in cents is ...
10d +100(16-d) = 520
-90d +1600 = 520 . . . . . eliminate parentheses, collect terms
-90d = -1080 . . . . . . . . . . subtract 1600
d = -1080/-90 = 12 . . . . . divide by the coefficient of d
Lily has 12 ten-cent coins.
Answer:
b
Step-by-step explanation:
Answer:
yes hes correct.
Step-by-step explanation:
37x8=296. 296+200= 596. 596>500
Answer:
Answer:
safe speed for the larger radius track u= √2 v
Explanation:
The sum of the forces on either side is the same, the only difference is the radius of curvature and speed.
Also given that r_1= smaller radius
r_2= larger radius curve
r_2= 2r_1..............i
let u be the speed of larger radius curve
now, \sum F = \frac{mv^2}{r_1} =\frac{mu^2}{r_2}∑F=
r
1
mv
2
=
r
2
mu
2
................ii
form i and ii we can write
v^2= \frac{1}{2} u^2v
2
=
2
1
u
2
⇒u= √2 v
therefore, safe speed for the larger radius track u= √2 v
Because of the relatively large coefficients {9, 42, 49}, applying the quadratic formula would be a bit messy. Instead, I've chosen to "complete the square:"
9x^2 + 42x + 49 = 0 can be re-written as 9 [ x^2 + (42/9)x ] = -49
Dividing both sides by 9, we get [ x^2 + (42/9)x ] = - 49/9
Completing the square: [ x^2 + (42/9)x + (21/9)^2 - (21/9)^2 ] = -49/9
[ x + 21/9 ]^2 = 441/81 - 441/81 = 0
Then [ x + 21/9 ] = 0, and x = -21/9 (this is a double root).
