C because the cost of the private school divided by 4 is 24,618
Answer:
Use desmos graphing calculator
Step-by-step explanation:
11) -x + y = -1 ; 2x - y = 0
y = -1 + x ; 2x - (-1+x) = 0 ⇒ 2x + 1 - x = 0 ⇒x = -1
y = -1 + (-1) ⇒ y = -2
12) -2x + y = -20 ; 2x + y = 48
y = -20 + 2x ; 2x + (-20 + 2x) = 48 ⇒ 2x -20 + 2x = 48 ⇒ 4x = 48 + 20
4x = 68 ⇒ x = 68/4 ⇒ x = 17
y = -20 + 2(17) ⇒ y = -20 + 34 ⇒ y = 14
13) 3x -y = -2 ; -2x + y = 3
y = 3 + 2x ; 3x - (3 + 2x) = -2 ⇒ 3x - 3 - 2x = -2 ⇒ x = -2 + 3 ⇒ x = 1
y = 3 + 2(1) ⇒ y = 3 + 2 ⇒ y = 5
14) x - y = 4 ; x - 2y = 10
x = 4 + y ; (4 + y) - 2y = 10 ⇒ 4 + y - 2y = 10 ⇒ 4 - y = 10
⇒ -y = 10 - 4 ⇒ -y = 6 ⇒ y = -6
x = 4 + (-6) ⇒ x = 4 - 6 ⇒ x = -2
15) x + 2y = 5 ; 3x + 2y = 17
x = 5 - 2y ; 3(5-2y) + 2y = 17 ⇒ 15 - 6y + 2y = 17 ⇒ -4y = 17 - 15
⇒ -4y = 2 ⇒ y = -2/4 ⇒ y = -1/2
x = 5 - 2(-1/2) ⇒ x = 5 + 2/2 ⇒ x = 5 + 1 ⇒ x = 6
Answer:
81 ............................
Answer:
12
Step-by-step explanation:
Step 1:
They spilt 1/5 on the way to the lemonade stand.
180 x 1/5
= 180/5
= 36
So they spilt 36 cups of lemonade on the way to the stand.
Number of cups left = 180 - 36
= 144
Step 2:
They sold 75% of 144 cups of lemonade
75/100 x 144 (divide both 75 and 100 by 25)
= 3/4 x 144 (divide 144 by 4)
= 3 x 36
= 108
So they sold 108 cups of lemonade.
Number of cups left = 144-108
= 36
Step 3:
They spilt 1/3 of 36 cups of lemonade on the way home.
36 x 1/3
= 36/3
= 12
Therefore they brought back 12 cups of lemonade home.
