I would solve the first equation for x and then sub that value into x in the second equation. That's the easiest way. x - 2y = 3 solved for x is x = 2y+3. Now sub that in for x in the second equation: 5(2y+3)+3y=2 and 10y + 15 + 3y = 2. 13y = -13, and y = -1. Now sub that y value into either equation to solve for x: x = 2(-1) + 3 gives us an x value of x = 1. Therefore, your solution to this system is (1, -1), first choice above.
Split up each force into horizontal and vertical components.
• 300 N at N30°E :
(300 N) (cos(30°) i + sin(30°) j)
• 400 N at N60°E :
(400 N) (cos(60°) i + sin(60°) j)
• 500 N at N80°E :
(500 N) (cos(80°) i + sin(80°) j)
The resultant force is the sum of these forces,
∑ F = (300 cos(30°) + 400 cos(60°) + 500 cos(80°)) i
… … … + (300 sin(30°) + 400 sin(60°) + 500 sin(80°)) j N
∑ F ≈ (546.632 i + 988.814 j) N
so ∑ F has a magnitude of approximately 1129.85 N and points in the direction of approximately N61.0655°E.
17. (a) The formula with CP subject is 
(b) The Cost Price of item without GST is $59.50
(c) The GST of item is $5.95
Step-by-step explanation:
Given formula is;
SP = 1.1 * CP
SP = Selling price
CP = Cost price
(a) Rearrange the formula to make CP the subject;
SP = 1.1 * CP
Dividing both sides by 1.1

The formula with CP subject is 
(b) Use your formula from (a) to find the Cost Price of an item without GST if the selling price is $65.45
SP = $65.45

The Cost Price of item without GST is $59.50
(c) Calculate the amount of GST on an item whose selling price is $65.45.
GST = 10% of CP
GST = 
GST = 0.1CP
From part (b)
CP = $59.50
GST = 0.1 * 59.50
GST = $5.95
The GST of item is $5.95
Keywords: percentage, multiplication
Learn more about multiplication at:
#LearnwithBrainly
Answer:
Step-by-step explanation:
a + 143 = 180 {Linear pair}
a = 180 - 143
a = 37
37 + 93 + b = 180 {Angle sum property of triangle}
130 + b = 180
b = 180 - 130
b = 40
c + b = 90
c + 40 = 90
c = 90 - 40
c = 50
d + 120 = 180 {Linear pair}
d = 180 - 120
d = 60
? = 60 + 40 {Exterior angle property of triangle}
? = 100
3(k-x)= -3x-9
3k - 3x = -3x - 9 ← equation without parentheses
3k - 3x + 3x = - 9
3k = -9
k = -9/3
k = -3 ← simplest form