This is an answer of this question
Answer:
8x² - 15y² + xy
Step-by-step explanation:
(4x + 5y) (2x - 3y) + 3xy
multiplying the terms in brackets
(4x) (2x - 3y) + (5y) (2x - 3y) + 3 xy
multiplying with each terms inside the bracket
(4x)(2x) - (4x) (3y) + (5y) (2x) - (5y) (3y) + 3xy
doing the product each of the pair of terms
8x² - 12xy + 10xy - 15y² + 3xy
taking the sum of terms with coefficient "xy"
8x² - 15y² -2xy + 3xy
8x² - 15y² + xy
Answer:
$22.33
Step-by-step explanation:
A 20% tip would be 0.20. Multiply the cost by 0.20 to get the tip amount or multiply the cost by 1.20 to get the total amount including tip.
subtotal --> $18.61
tip --> $3.72
18.61 x 0.20 = 3.72
total --> $22.33
Answer:
Here we have the function:
S(t) = 500 - 400*t^(-1)
Then the rate of change at the value t, will be:
S'(t) = dS(t)/dt
This differentiation will be:
S'(t) = -400/t^2
Then:
a) the rate of change at t = 1 is:
S'(1) = -400/1^2 = -400
The rate of change after one year is -400
b) t = 10
S'(10) = -400/10^2 = -400/100 = -4
The rate of change after 10 years is -4, it reduced as the years passed, as expected.