Answer:
see explanation
Step-by-step explanation:
Given the 2 equations
5x + y = 21 → (1)
x - 3y = 9 → (2)
Multiply (1) by 3 and add the result to (2) to eliminate y term
15x + 3y = 63 → (3)
Add (2) and (3) term by term
(x + 15x) + )- 3y + 3y) = (9 + 63)
16x = 72 ( divide both sides by 16 )
x = 4.5
Substitute x = 4.5 into (1) for corresponding value of y
22.5 + y = 21 ( subtract 22.5 from both sides )
y = - 1.5
Solution is (4.5, - 1.5 )
The answer to the question
Answer: y=1/2x-1
Step-by-step explanation:
To find the equation of the line that passes through the points, we need to find out slope, m.

We plug our points into this formula to find slope.

Our slope is 1/2. To find our y-intercept, b, we would plug any point into the equation for slope-intercept form.
y=mx+b
y=1/2x+b
1=1/2(4)+b
1=2+b
b=-1
Now that we know b, our equation is y=1/2x-1.
Answer:
1, 2, 3
Step-by-step explanation:
X <= 20 means that x has to be less than OR equal to 20.
The first option is -100. That's less than 20, so this statement is true.
The second option is 10. That's also less than 20, so this statement is also true.
The third option is 20. This is equal to 20, so this is also true.
The fourth option is 21, which is greater than 20, so it's not true.
The fifth option is 45, which is greater than 20, so it's not true.
Sorry I answered so late, hope this helps even though you probably don't need it anymore.
Answer:
108, 108, 72
Step-by-step explanation:
Vertical angles are congruent and if the measure of 1 of the angles is 72 degrees and straight lines equal 180 degrees you have to subtract 72 from 180 which equals 108.