The answer is either b or c
Step-by-step explanation:
- 2x-2y=-6
3x+4y=8
multiply equation (1) by 3 and equation (2) by 2
- 6x-6y=18
6x+8y=16
Add
2y=34
y= 34÷2
y=17
substitute 17 for y in equation (2)
3x+4y=8
3x+4(17)=8
3x+68=8
3x=8-68
3x=-60
x=-60÷3
x=-20
x=-20,y=17
Answer:
10
Step-by-step explanation:
Question:
The quantities x and y are proportional.
x y
5.8 7.5
11.2
Find the constant of proportionality (r) in the equation y=rx
Answer:
The constant of proportionality is 75/58 or 1.29
Step-by-step explanation:
Given
The table above
Required
Find the constant of proportionality
The question has an incomplete table but it can still be solved because x and y are proportional.
Given that
y = rx
Make r the subject of formula
Divide through by x
y/x = rx
y/x = r
r = y/x
When y = 7.5, x = 5.8
Substitute these values
r = y/x becomes
r = 7.5/5.8
Multiply denominator and numerator by 10
r = (7.5 * 10)/(5.8 * 10)
r = 75/58
In this case, it's best to leave the answer in fraction.
However, it can be solved further.
r = 75/58
r = 1.29 (Approximated)
Hence, the constant of proportionality is 75/58 or 1.29
