Answer:
x = - 16
Step-by-step explanation:
The equation relating two proportional quantities is
y = kx ← k is the constant of proportionality
To find k use the condition when y = 1, x = - 4
k = 
= - 
y = - x ← equation of proportionality
when y = 4, then
4 = - x (multiply both sides by - 4 )
x = - 16
Question:
The quantities x and y are proportional.
Find the constant of proportionality (r)
Answer:
Step-by-step explanation:
Given
Required
Determine the constant of proportionality (r)
Constant of proportionality (r) is calculated as
When
Substitute these values in the given formula
Convert both fractions to improper fractions
Multiply both sides by 
Reorder
Divide the numerator and denominator by 3
Convert to mixed fraction
<em>Hence, the constant of proportionality is </em>
<em></em>
Answer: (i) 4x - 40 = 76
(ii) 29 questions
Step-by-step explanation:
Let the total number of questions be x.
Since he received 4 points for every correct answer and he got 10 answers wrong , this means he lost 40 points , the equation thus become
4x - 40 = 76
To find the value of x , add 40 to both sides
4x = 116
divide through by 4
x = 29
Therefore , there are 29 questions on his math test
Answer:
19/1 or 1.9
Step-by-step explanation:
Answer: x = 0, y = 7
-x+y=7
add x to both sides
y=x+7
plug this in for y in the other equation
6x-(x+7)=-7
simplify
6x-x-7=-7
simplify
5x-7=-7
add 7 to both sides
5x=0
divide both sides by 5
x=0
plug in to one of the equations to find y
-(0)+y=7
y=7
Therefore, x=0 and y=7.
Hope this helps!
