we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=kx
Verify each table
Remember that
In a proportional relationship, the linear equation passes through the origin (0,0)
we have that
Am B and C passes through the origin
so
I will check table D
we have the points
(10,30) and (15,45)
Find the slope
m=(45-30)/(15-10)
m=15/5
m=3
Find the equation in slope intercept form
y=mx+b
we have
m=3
point (10,30)
substitute
30=3(10)+b
b=0
y=3x
Verify with this equation for the other points
For x=100
y=3(100)=300 ----> is ok
For x=200
y=3(200)=600 ----> is ok
that means
table D is proportional
Verify table C
we have
(0,0) and (1,3)
m=(3-0)/(1-0)
m=3
Find the equation in slope intercept form
y=mx+b
we have
m=3
point (0,0)
y=3x
Verify the other points
For x=2
y=2(3)=6
6 is not equal to 9
that means
table C is not proportiona
answer is C
A = 1/2 hb
20 = 1/2 x 4 x b
20 = 2 b
b = 20 /2
b = 10
answer is <span>10 m</span>
