7(x + 2) = 6(x + 5)
7x + 14 = 6x + 30 |subtract 14 from both sides
7x = 6x + 16 |subtract 6x from both sides
x = 16
Answer: An adult’s ticket costs $9 while a children’s ticket costs $5.
Step-by-step explanation:
1). 2x + 3y = 33
2). 5x + 2y = 55
3). I’m going to use substitution.
Isolate a variable (x):
2x + 3y = 33
2x = -3y + 33
X = (-3y + 33)/2
X = -3/2y + 33/2
Substitute and solve for y:
5x + 2y = 55
5(-3/2y + 33/2) + 2y = 55
-15/2y + 165/2 + 2y = 55
-11/2y = -55/2
Y = 5 <— children’s ticket.
Solve for x:
2x + 3y = 33
2x + 3(5) = 33
2x + 15 = 33
2x = 18
X = 9 <— adult’s ticket.
Check:
5x + 2y = 55
5(9) + 2(5) = 55
45 + 10 = 55
55 = 55
2x + 3y = 33
2(9) + 3(5) = 33
18 + 15 = 33
33 = 33
Answer:
........................................................................................
Step-by-step explanation:
8.9
The equation for the grain size is expressed as the equality:
Nm(M/100)^2 = 2^(n-1)
where
Nm = number of grains per square inch at magnification M.
M = Magnification
n = ASTM grain size number
Let's solve for n, then substitute the known values and calculate.
Nm(M/100)^2 = 2^(n-1)
log(Nm(M/100)^2) = log(2^(n-1))
log(Nm) + 2*log(M/100) = (n-1) * log(2)
(log(Nm) + 2*log(M/100))/log(2) = n-1
(log(Nm) + 2*log(M/100))/log(2) + 1 = n
(log(33) + 2*log(270/100))/log(2) + 1 = n
(1.51851394 + 2*0.431363764)/0.301029996 + 1 = n
(1.51851394 + 0.862727528)/0.301029996 + 1 = n
2.381241468/0.301029996 + 1 = n
7.910312934 + 1 = n
8.910312934 = n
So the ASTM grain size number is 8.9
If you want to calculate the number of grains per square inch, you'd use the
same formula with M equal to 1. So:
Nm(M/100)^2 = 2^(n-1)
Nm(1/100)^2 = 2^(8.9-1)
Nm(1/10000) = 2^7.9
Nm(1/10000) = 238.8564458
Nm = 2388564.458
Or about 2,400,000 grains per square inch.
Answer:
4 ft downwards
Step-by-step explanation:
old height off the ground :
7^2+b^2=25^2
49+b^2=625
b^2=576
b=24
new height off the ground :
7+8=15
15^2+ b^2 =25^2
225+b^2 = 625
b^2 = 400
b=20
difference between heights :
24 - 20 = 4
