Answer:
Step-by-step explanation:
y=x²-2x-1
and y=-3x+5
x²-2x-1=-3x+5
x²+x-6=0
x²+3x-2x-6=0
x(x+3)-2(x+3)=0
(x+3)(x-2)=0
x=-3,2
when x=-3
y=-3×-3+5=9+5=14
when x=2
y=-3×2+5=-6+5=-1
so solutions are (-3,14) and (2,-1)
Answer:
cost of one medium drink = $3.80
cost of one large popcorn = $6.25
Step-by-step explanation:
Let D = cost of one medium drink
Let P = cost of one large popcorn
If a couple bought 2 medium drinks and a large popcorn for $13.85:
⇒ 2D + P = 13.85
If a family bought 3 medium drinks and 2 large popcorn for a total of $23.90:
⇒ 3D + 2P = 23.90
Rewrite 2D + P = 13.85 to make P the subject:
⇒ P = 13.85 - 2D
Substitute into 3D + 2P = 23.90 and solve for D:
⇒ 3D + 2(13.85 - 2D) = 23.90
⇒ 3D + 27.7 - 4D = 23.90
⇒ D = 3.8
Substitute found value of D into P = 13.85 - 2D to find P:
⇒ P = 13.85 - (2 x 3.8) = 6.25
Therefore,
cost of one medium drink = $3.80
cost of one large popcorn = $6.25
Answer:
No
Step-by-step explanation:
Because 0.3 is a decimal and 18 is a whole number.
0.3 = 3/10 which is 30%
There are 72 green pens.
There is 9 times as many white pens from 2 to 18, so there has to be 9 times as many green pens because of the ratio. 9 times 8 is 72.
