Answer:
1) Words learned=15x+75
2) 15 is the slope
3) 270 words
4) 21 weeks
Explanation:
Let x be equal to the number of weeks that pass.
Let y be equal to the number of words we learn.
1) We're told that we learn 15 words per week. Therefore, 15x would equal the number of words we learn. However, because we already know 75, we add that to 15x, giving us this equation:
y=15x+75
2) The slope is the same thing as the rate of change in a situation. In this scenario, every week, we learn 15 words. Therefore, the rate of change, or the slope, is 15.
3) To find this, plug 13 into our equation as x and solve for y.
y=15x+75
y=15(13)+75
y=195+75
y=270
Therefore, we would learn 270 vocabulary words in total in 13 weeks.
4) To find this, plug 390 into our equation as y and solve for x.
y=15x+75
390=15x+75
Subtract 75 on both sides to isolate x
390-75=15x+75-75
315=15x
Divide both sides by 15
315/15=15x/15
21=x
Therefore, it would take 21 weeks to learn 390 new vocabulary words.
I hope this helps!