Answer:
All results in the explanation
Step-by-step explanation:
To make the equation of the line, we only need two points. Select from the table the points (-1,4) and (3,9).
First, find the slope of the line:
We know the line passes through points A(x1,y1) and B(x2,y2). The slope can be calculated with the equation:
\begin{gathered}\displaystyle m=\frac{y_2-y_1}{x_2-x_1}\\\end{gathered}m=x2−x1y2−y1
Substituting:
\displaystyle m=\frac{9-4}{3+1}=\frac{5}{4}m=3+19−4=45
This value is used in the slope-point form of the line:
\displaystyle y-k=\frac{5}{4}(x-h)y−k=45(x−h)
Where (h,k) is a point from the table, select for example (3,9):
\displaystyle y-9=\frac{5}{4}(x-3)y−9=45(x−3)
Operate:
\displaystyle y=\frac{5}{4}\cdot x-\frac{5}{4}\cdot 3+9y=45⋅x−45⋅3+9
\displaystyle y=\frac{5}{4}\cdot x+\frac{-15+36}{4}y=45⋅x+4−15+36
The equation of the line is:
\boxed{\displaystyle y=\frac{5}{4}\cdot x+\frac{21}{4}}y=45⋅x+421
Now complete the table.
For x=0:
\displaystyle y=\frac{5}{4}\cdot 0+\frac{21}{4}y=45⋅0+421
y=\frac{21}{4}y=421
For x=15
\displaystyle y=\frac{5}{4}\cdot 15+\frac{21}{4}y=45⋅15+421
\displaystyle y=\frac{75}{4}+\frac{21}{4}=\frac{96}{4}=24y=475+421=496=24
y=24
For y=1.5, find x:
\displaystyle 1.5=\frac{5}{4}\cdot x+\frac{21}{4}1.5=45⋅x+421
Operate:
\displaystyle 1.5-\frac{21}{4}=\frac{5}{4}\cdot x1.5−421=45⋅x
Multiply by 4:
\displaystyle 6-21=5 x6−21=5x
Solve:
x=-15/5=-3x=−15/5=−3
x=-3
