The general form of the equation of a straight line in the slope-intercept form is given to be:
![y=mx+b](https://img.qammunity.org/2023/formulas/mathematics/high-school/smsb8cbft03lwblmi49nf2l6jby2ofxzws.png)
where m is the slope of the line and b is the intercept on the y-axis, that is the y-value when x = 0.
To calculate the slope, we can use the formula:
![m=(y_2-y_1)/(x_2-x_1)](https://img.qammunity.org/2023/formulas/mathematics/high-school/78uaqhwt0aws3qfwxigaftpihnmb1gzxtp.png)
From the question provided, we have the points:
![\begin{gathered} 1\Rightarrow(x_1,y_1)=(-1,-2) \\ 2\Rightarrow(x_2,y_2)=(3,4) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/uf33wzmwhmvm9vfls8v3p6e4ffzis27t5l.png)
Using these values, we can calculate the slope to be:
![m=(4-(-2))/(3-(-1))=(4+2)/(3+1)=(6)/(4)=(3)/(2)](https://img.qammunity.org/2023/formulas/mathematics/college/fv0ac49ix6zod5otikbbu2xj5yfb5ymj52.png)
Hence, we have the equation of the line to be:
![y=(3)/(2)x+b](https://img.qammunity.org/2023/formulas/mathematics/college/b8oywr1kvke93stf7dhoxsaqbmwa53pg0q.png)
We currently do not have a value for b. We can find b, however, by substituting a point into the equation. Then we can solve for b. Using the second point, we have:
![\begin{gathered} 2\Rightarrow(x,y)=(3,4) \\ \therefore \\ 4=(3)/(2)(3)+b \\ 4=(9)/(2)+b \\ b=4-(9)/(2) \\ b=-(1)/(2) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/q3fkxi79vb24vvz2df3cdc7pafuht8x1hx.png)
Therefore, the equation of the line is:
![\begin{gathered} y=(3)/(2)x-(1)/(2) \\ or \\ y=1.5x-0.5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1ctw6ggw6hxze28hglx45xss9k3bedns92.png)