Answer:
b. [tex]y=6x+50[/tex]
Step-by-step explanation:
Let x represent the number of weeks and y represent the total amount in Catherine's account.
We have been given a table that shows the money saved by Catherine in her saving accounts.
We will represent the amount of money saved by Catherine in her savings account in slope-intercept form of equation: [tex]y=mx+b[/tex], where m represents slope and b represents y-intercept.
Let us find the slope of line using slope formula.
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex], where,
[tex]y_2-y_1[/tex] = Difference between two y-coordinates.
[tex]x_2-x_1[/tex] = Difference between same x-coordinates of two y-coordinates.
Upon substituting coordinates of points (4,74) and (11,116) in slope formula we will get,
[tex]m=\frac{116-74}{11-4}[/tex]
[tex]m=\frac{42}{7}[/tex]
[tex]m=6[/tex]
Let us substitute [tex]m=6[/tex] and coordinates of point (4,74) in slope intercept form of equation to find y-intercept or initial amount of money,
[tex]74=6*4+b[/tex]
[tex]74=24+b[/tex]
[tex]74-24=24-24+b[/tex]
[tex]50=b[/tex]
Upon substituting [tex]b=50[/tex] and [tex]m=6[/tex] in slope-intercept form of equation we will get,
[tex]y=6x+50[/tex]
Therefore, the equation [tex]y=6x+50[/tex] represents the total amount (y) in Catherine's account after x weeks and option b is the correct choice.