Answer:
- 2/5x=7/20x+1/4
- -3/4=-1/20x-1/2
- -3/4+1/20x=-1/2
Step-by-step explanation:
If you add 3/4 to both sides of the equation, you get ...
... 2/5x = 7/20x + 1/4 . . . . first choice
If you subtract 2/5x from both sides of the equation, you get ...
... -3/4 = -1/20x -1/2 . . . . third choice
If you subtract 7/20x from both sides of the equation, you get ...
... -3/4 +1/20x = -1/2 . . . . last choice
Choices 2 and 4 are erroneous versions of choices 1 and 3, so do not apply.
Answer:
10 books approx
Step-by-step explanation:
Step one:
Given data
Hight of cupboard= 1.21m
Thickness of book= 12.5cm
thickness in meters= 12.5/100= 0.125m
Required
The number of books need to fill the Cupboard
Step two:
the number of books can be computed as
= 1.21/0.125
=9.68 book
=10 books approx
Ni : Zn: Cu = 7:2:9 =7x : 2x : 9x
7x+2x+9x = 3.8
18x=3.8
x=3.8/18=1.9/9≈0.21
Ni: 7x=7*0.21=1.47 ≈1.5 kg
Zn: 2x=2*0.21=0.42≈0.4 kg
Cu: 9x=9*0.21=1.89 ≈1.9 kg
Check 1.5+0.4+1.9 =3.8 True
C. $112.50
y=0.25x+50
x = 250 miles
0.25*250=62.50
62.50+50= $112.50