<h3>
Answer: 216 square feet</h3>
Work Shown:
Old area = 12*15 = 180 square feet
New area = 18*22 = 396 square feet
Difference = New - Old = 396 - 180 = 216
The patio's area increased by 216 square feet.
Answer:
Step-by-step explanation:
In the fifth grade class, 
of the girls have brown hair. Again among those of the brown-haired girls, 
of them have long hair.
We are asked to find the fraction of the girls who have long brown hair in the class.
The fraction of the total students which have long brown hair will be (
) = . (Answer)
This formula solve by discriminant (D=b^2-4ac)
We can use linear combinations of the equations to eliminate variables.
3x - 4y = 1
-2x + 3y = 1
To eliminate y we'll make the linear combination of 3 times the first equation minus four times the second.
9x - 12y = 3
-8x + 12y = 4
Adding,
x = 7
We could solve for y directly but let's use another linear combination, twice the first plus three times the second:
2(3x - 4y) + 3(-2x + 3y)= 2(1)+3(1)
y = 5
Check: 3(7)-4(5)=1 good. -2(7)+3(5)=1 good.
Q18 Answer: (7,5)
y = -3x + 5
5x - 4y = -3
4y +1(5x - 4y) = 4(-3x + 5) + 1(-3)
5x = -12x + 20 -3
17 x = 17
x = 1
y = -3(1) + 5 = 2
Check: 5(1) - 4(2) = -3 good
Q19 Answer (1,2)
6x + 5y = 25
x = 2y + 24
6x = 12y + 144
5y = 25 - 12y - 144
17y = -119
y = -119/17= -7
x = 2y+24= 10
Check: 6(10)+5(-7)=25 good 2y+24=2(-7)+24=10=x good
Q20 Answer (10,-7)
3x + y = 18
-7x + 3y = -10
9x + 3y = 54
9x - -7x = 54 - -10
16x = 64
x=4
y = 18 -3x = 18-12=6
Check: 3(4)+6=18 good, -7(4)+3(6)=-10 good
Q21 Answer: (4,6)
Answer:
$15 in debt
Step-by-step explanation:
Subtract 33 from 18
18 - 33
= -15
So, he will be $15 in debt
