If the width is 15, and the scale factor from width to length is 3:2, then you will have to divide 15 by 3 to get your original width.
15/3 = 5.
5 is your original width.
4.0081 x 10 to the 4th power. I know because I did this one.
Distribute 2 and remove parentheses :
1/2x+8=3x-6
Multiply both sides of equation by 2:
x+16=6x-12
Move terms:
x+16-6x=-12
x-6x=-12-16
Collect like terms:
-5x=-28
Divide both sides:
x=28/5
Answer:
45 girls
Step-by-step explanation:
- Remark
- There are only 2 choices for gender. So if the class is 60% girls, the there must be 100 - 60 = 40% for the boys.
- But we are told that the boys are 30 in number.
- Let x = the total number of students.
Solution
- 40/100 * x = 30 Change the % to a decimal
- 0.4 x = 30 Divide both sides by 0.4
- 0.4 x / 0.4 = 30 / 0.4 Do the division
- x = 30/0.4
- x = 75 students in total
Formula
Total of Boys and Girls = Number of boys + number of girls.
Givens
- Total = 75
- Number of boys = 30
Solution II
- 75 = x + 30 Subtract 30 from each side
- 75 - 30 = x +30 - 30
- 45 = x
- There are 45 girls in the class.
The formula to calculate the amount is 1200(1+0.03/4)^5
