(2-5i)(3+i)
use foil method to expand it into standard form
6+2i-15i+5i^2
5i^2-13i+6
Answer:
300 girls were there in the gym.
Step-by-step explanation:
Given:
The ratio of the number of boys to the number of girls was 4:3, after 160 boys left the gym, the ratio became 4:5.
Now, to find the number of girls in the gym.
The girls in the gym does not left, their quantity is same before and after.
So, we multiply the both ratios to make the girls ratio same:
4:3 × 5 = 20:15
4:5 × 3 = 12:15
Now, <em>we find the units of the ratio</em>.
<em>The ratio of boys dropped down by 160</em>:
20 - 12 = 8 units.
160 = 8 units
Now, dividing both sides by 8 we get:
20 = 1 unit
So, 1 unit = 20.
Now, girls = 15 units
So, 15 × 20 = 300.
Therefore, 300 girls were there in the gym.
Answer:
Solution :
{x,y} = {0/14261512,4}
Step-by-step explanation:
Solve by Substitution :
// Solve equation [2] for the variable y
[2] y = x + 4
// Plug this in for variable y in equation [1]
[1] 12x - 5•(x +4) = -20
[1] 7x = 0
// Solve equation [1] for the variable x
[1] 7x = 0
[1] x = 0
// By now we know this much :
x = 0
y = x+4
// Use the x value to solve for y
y = (-0/14261512)+4 = 4
Answer:
113.1
Step-by-step explanation:
A = πr²
A = π (6)²
A = π (36)
A = 113.09 = 113.1
