Answer:
- 20 + 8i
Step-by-step explanation:
Noting that i² = - 1
Given
[(6i + 9) + (4i - 5)] × 2i ← evaluate the terms inside the square bracket
= ( 6i + 9 + 4i - 5 ) × 2i
= (10i + 4) × 2i ← multiply each term in the parenthesis by 2i
= 20i² + 8i
= 20(- 1) + 8i
= - 20 + 8i
Are you trying to solve for x and y?
y=2x+1; x+2y=17
sub in one variable in the other equation.
x+2(2x+1)=17
x+4x+2=17
5x=15
x=3
now that you have x value, plug into the original equation to find y and check with the other.
y=2(3)+1 = 7
x+2y=17 = 3 + 2(7) = 17 ; 17=17
Answer:
y=
- 2
Step-by-step explanation:
This is correct
9514 1404 393
Answer:
$125 per year
Step-by-step explanation:
In the 2 years from 2015 to 2017, the spending on lunches increased by ...
$800 -550 = $250
That is an average per year of ...
$250/(2 yr) = $125/yr . . . . average dollar increase per year
_____
<em>Additional comment</em>
For costs, it is often true that they follow an exponential curve, not a linear one. Ed's spending increased by a factor of 800/550 = 16/11 in the two years, so an average percentage increase of √(16/11) -1 = 20.6% per year.