Answer:
- 494
Step-by-step explanation:
Breaking down the summation into it;s component parts
= 4k - 
k(k + 1) ← substitute k = 19
= (4 × 19 ) - 1.5 × (19 × 20)
= 76 - (1.5 × 380)
= 76 - 570
= 494
139 is suppose to be 140 and 18 is suppose to be 20, 140 x 20 = 2800
Home this works
Answer:
=========
<h2>Given</h2>
<h3>Line 1</h3>
<h3>Line 2</h3>
- Passing through the points (4, 3) and (5, - 3)
<h2>To find</h2>
- The value of k, if the lines are perpendicular
<h2>Solution</h2>
We know the perpendicular lines have opposite reciprocal slopes, that is the product of their slopes is - 1.
Find the slope of line 1 by converting the equation into slope-intercept from standard form:
<u><em>Info:</em></u>
- <em>standard form is ⇒ ax + by + c = 0, </em>
- <em>slope - intercept form is ⇒ y = mx + b, where m is the slope</em>
- 3x - ky + 7 = 0
- ky = 3x + 7
- y = (3/k)x + 7/k
Its slope is 3/k.
Find the slope of line 2, using the slope formula:
- m = (y₂ - y₁)/(x₂ - x₁) = (-3 - 3)/(5 - 4) = - 6/1 = - 6
We have both the slopes now. Find their product:
- (3/k)*(- 6) = - 1
- - 18/k = - 1
- k = 18
So when k is 18, the lines are perpendicular.
Answer:
You have to pay close attention to the Order of Operations.
10(6+4)/2. Grouping symbols first.
6+4=10.
10(10)/2
10*10=100.
100/2.
50 is your answer
Step-by-step explanation:
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Answer:
There were 26 students in his class and the teacher had 83 ml of the solution.
Step-by-step explanation:
Mr. Kohl has a "x" amount of solution, if he divides it by the number of students "n" he'll give each student 3 milliliters and have a left over of 5 milliliters. If the amount of solution Mr. Kohl had was "x + 21" then he'd be able to give each student 4 milliliters of the solution. From these informations we have:
x = 3*n + 5
(x + 21)/n = 4
x + 21 = 4*n
x = 4*n - 21
Now that we have two equations and two variables we can solve the system of equations, as seen bellow:
3*n + 5 = 4*n - 21
3*n - 4*n = -21 - 5
-n = -26
n = 26
x = 4*26 - 21 = 83 ml
There were 26 students in his class and the teacher had 83 ml of the solution.
