-3x(-7) = -3(-2)(-7) ⇒ -42
-42 would be the answer.
to get the slope of any line, all we need is two points off of it, so let's get the slope and thus its equation, hmmmm let's see points (-2,-3) and the origin are the obvious ones =)
![\bf (\stackrel{x_1}{-2}~,~\stackrel{y_1}{-3})\qquad (\stackrel{x_2}{0}~,~\stackrel{y_2}{0}) \\\\\\ slope = m\implies \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{0-(-3)}{0-(-2)}\implies \cfrac{0+3}{0+2}\implies \cfrac{3}{2} \\\\\\ \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-(-3)=\cfrac{3}{2}[x-(-2)]\implies y+3=\cfrac{3}{2}(x+2) \\\\\\ y+3=\cfrac{3}{2}x+3\implies y=\cfrac{3}{2}x](https://tex.z-dn.net/?f=%5Cbf%20%28%5Cstackrel%7Bx_1%7D%7B-2%7D~%2C~%5Cstackrel%7By_1%7D%7B-3%7D%29%5Cqquad%20%28%5Cstackrel%7Bx_2%7D%7B0%7D~%2C~%5Cstackrel%7By_2%7D%7B0%7D%29%20%5C%5C%5C%5C%5C%5C%20slope%20%3D%20m%5Cimplies%20%5Ccfrac%7B%5Cstackrel%7Brise%7D%7B%20y_2-%20y_1%7D%7D%7B%5Cstackrel%7Brun%7D%7B%20x_2-%20x_1%7D%7D%5Cimplies%20%5Ccfrac%7B0-%28-3%29%7D%7B0-%28-2%29%7D%5Cimplies%20%5Ccfrac%7B0%2B3%7D%7B0%2B2%7D%5Cimplies%20%5Ccfrac%7B3%7D%7B2%7D%20%5C%5C%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7B%7Cc%7Cll%7D%20%5Ccline%7B1-1%7D%20%5Ctextit%7Bpoint-slope%20form%7D%5C%5C%20%5Ccline%7B1-1%7D%20%5C%5C%20y-y_1%3Dm%28x-x_1%29%20%5C%5C%5C%5C%20%5Ccline%7B1-1%7D%20%5Cend%7Barray%7D%5Cimplies%20y-%28-3%29%3D%5Ccfrac%7B3%7D%7B2%7D%5Bx-%28-2%29%5D%5Cimplies%20y%2B3%3D%5Ccfrac%7B3%7D%7B2%7D%28x%2B2%29%20%5C%5C%5C%5C%5C%5C%20y%2B3%3D%5Ccfrac%7B3%7D%7B2%7Dx%2B3%5Cimplies%20y%3D%5Ccfrac%7B3%7D%7B2%7Dx)
Note that when two lines have slopes of m₁ and m₂, then
(i) If m₁ = m₂, then the lines are parallel.
(ii) If m₁*m₂ = -1, then the lines are perpendicular.
Let us evaluate the given lines.
a. y = 4x - 1 and 12x = 3y + 7
y = 4x - 1 => m₁ = 4
Write the second equation in standard form.
3y = 12x - 7
y = 4x - 7/3 => m₂ = 4.
m₁ = m₂.
Answer: PARALLEL
b. x - 7y = 10 and 2x + 14y = 21
In standard form,
7y = x - 10 or y = (1/7)x - 10/7 => m₁ = 1/7
14y = - 2x + 21 or y = -1/7 + 3/2 => m₂ = -1/7
m₁ ≠ m₂ and m₁*m₂ ≠ -1.
Answer: NEITHER
c. 5x + 6y = 18 and 18x - 15y = 36
In standard form,
6y = -5x + 18 or y = -(5/6)x + 3 => m₁ = -5/6
15y = 18x - 36 or y = (6/5)x - 12/5 => m₂ = 6/5
m₁*m₂ = -1
Answer: PERPENDICULAR
d. x =1 and y = 1
x = 1 => m₁ is undefined
y = 1 => m₂ = 0
m₁ ≠ m₂ and m₁*m₂ ≠ -1
Answer: NEITHER
Divide 4.55 by 0.13 (the cost of each bolt) to find out how many bolts Heidi can buy!
$4.55 ÷ $0.13 = 35
Heidi can buy 35 bolts with $4.55 !1
Answer: x=18, R=20 degrees,
sin Q=3/5
cos Q=4/5
tan Q=3/4
sec Q=5/4
csc Q=5/3
cot Q=4/3
Step-by-step explanation:
Distance formula: a^2+b^2=c^2
30^2=24^2+x^2
900=576+x^2
x^2=324
x=18
180=P+Q+R
180=90+70+R
180=160+R
R=20 degrees
sin Q=18/30=3/5
cos Q=24/30=4/5
tan Q=18/24=3/4
sec Q=30/24=5/4
csc Q=30/18=5/3
cot Q=24/18=4/3
