<span>5x-6y=-15
5x+6y=12
---------------add
10x = -3
x = -3/10
x = -0.3
</span>5x+6y=12
5(-0.3) + 6y = 12
6y = 12 + 1.5
6y = 13.5
y = 13.5 / 6
y = 2.25
#22 is Ian. #23.a. is 77%. b. is Yes. c. is 16.
Remark
I'm going to interpret this equation as
D = ut + kt² The only difference is the 2.
Solution
Subtract kt² from both sides.
D - kt² = ut Now divide by u on both sides.
The t's cancel out. on the right. You are left with u on the right.
21:3
9:3
3:1
there all a 3:1 ratio
Answer: 16 men
32 women
38 children
Step-by-step explanation:
Let x represent the number of men in the group.
Let y represent the number if women in the group.
Let z represent the number of children in the group.
A group of 86 people consist of men women and children. This means that
x + y + z = 86 - - - - - - - - - - - - 1
There are twice as many women than there are men. It means that
x = y/2
There are 6 more children than there are women. This means that
z = y + 6
Substituting x = y/2 and z = y + 6 into equation 1, it becomes
y/2 + y + y + 6 = 86
multiplying through by 2, it becomes
y + 2y + 2y + 12 = 172
5y = 172 - 12 = 160
y = 160/5 = 32
x = y/2 = 32/2
x = 16
z = y + 6 = 32 + 6
z = 38
