Answer: it cost a customer $7.25 to buy five tulips and $10.5 to buy six roses.
Step-by-step explanation:
Let x represent the cost of 1 tulip.
Let y represent the cost of 1 rose.
The price of each tulip is the same and the price of each roses the same. One customer bought seven tulips and nine roses for $25.90. This means that
7x + 9y = 25.9 - - - - - - - - - - - - - - 1
Another customer bought for four tulips and eight roses for $19.80. This means that
4x + 8y = 19.8- - - - - - - - - - - - - - - 2
Multiplying equation 1 by 4 and equation 2 by 7, it becomes
28x + 36y = 103.6
28x + 56y = 138.6
Subtracting, it becomes
- 20y = - 35
y = - 35/ - 20
y = 1.75
Substituting y = 1.75 into equation 2, it becomes
4x + 8 × 1.75 = 19.8
4x + 14 = 19.8
4x = 19.8 - 14 = 5.8
x = 5.8/4
x = 1.45
The cost of 5 tulips would be
1.45 × 5 = $7.25
The cost of 6 roses would be
1.75 × 6 = $10.5
Answer:
the slope of the line y=8 is 0
Step-by-step explanation:
0
Answer: the speed of the boat on the lake is 9 mph
Step-by-step explanation:
Let x represent the speed of the boat on the lake or in still water.
The speed of the current in a river is 6 mph. This means that if the boat goes upstream against the speed of the current, its total speed would be (x - 6)mph. If the boat goes downstream against the speed of the current, its total speed would be (x + 6)mph.
Time = distance/ speed
Every day, his route takes him 22.5 miles each way against the current and back to his dock, and he needs to make this trip in a total of 9 hours. This means that the time taken to travel upstream is
22.5/(x - 6). The time taken to travel downstream is
22.5/(x + 6)
Since the total time is 9 hours, it means that
22.5/(x - 6) = 22.5/(x + 6)
Cross multiplying, it becomes
22.5(x + 6) + 22.5(x - 6) = 9
Multiplying through by (x + 6)(x - 6), it becomes
22.5(x - 6) + 22.5(x + 6) = 9[(x + 6)(x - 6)]
22.5x - 135 + 22.5x + 135 = 9(x² - 6x + 6x - 36)
22.5x + 22.5x = 9x² - 324
9x² - 45x - 324 = 0
Dividing through by 9, it becomes
x² - 5x - 36 = 0
x² + 4x - 9x - 36 = 0
x(x + 4) - 9(x + 4) = 0
x - 9 = 0 or x + 4 = 0
x = 9 or x = - 4
Since the speed cannot be negative, then x = 9
1)
x^2 + 4x - 5
y = --------------------
3x^2 - 12
Vertcial asym => find the x-values for which the equation is not defined and check whether the limit goes to + or - infinite
=> 3x^2 - 12 = 0 => 3x^2 = 12
=> x^2 = 12 / 3 = 4
=> x = +/-2
Limit of y when x -> 2(+) = ( 2^2 + 4(2) - 5) / 0 = - 1 / 0(+) = ∞
Limit of y when x -> 2(-) = - 1 / (0(-) = - ∞
Limit of y when x -> - 2(+) = +∞
Limit of y when x -> - 2(-) = -
=> x = 2 and x = - 2 are a vertical asymptotes
Horizontal asymptote => find whether y tends to a constant value when x -> infinite of negative infinite
Limi of y when x -> - ∞ = 1/3
Lim of y when x -> +∞ = 1/3
=> Horizontal asymptote y = 1/3
x - intercept => y = 0
=>
x^2 + 4x - 5
0 = ------------------ => x ^2 + 4x - 5 = 0
3x^2 - 12
Factor x^2 + 4x - 5 => (x + 5) (x - 1) = 0 => x = - 5 and x = 1
=> x-intercepts x = - 5 and x = 1
Domain: all the real values except x = 2 and x = - 2
2) y = - 2 / (x - 4) - 1
using the same criteria you get:
Vertical asymptote: x = 4
Horizontal asymptote: y = - 1
Domain:all the real values except x = 4
Range: all the real values except y = - 1
3)
x/ (x + 2) + 7 / (x - 5) = 14 / (x^2 - 3x - 10)
factor x^2 - 3x - 10 => (x - 5)(x + 2)
Multiply both sides by (x - 5) (x + 2)
=> x(x - 5) + 7( x + 2) = 14
=> x^2 - 5x + 7x + 14 = 14
=> x^2 + 2x = 0
=> x(x + 2) = 0 => x = 0 and x = - 2 but the function is not defined for x = - 2 so it is not a solution => x = 0
Answer: x = 0
