By the end of your 5th French lesson, you have learned 20 vocabulary words. After 10 lessons you know 40 vocabulary words. Write an equation that gives the number of vocabulary words you know, y, in the terms of the number of lessons you had, x.
algebra - Reiny, Wednesday, November 18, 2009 at 10:12pm
Assuming that the learning of vocabulary words increases in a linear pattern, (it does not), you have two ordered pairs.
(5,20) and (10,40)
Just like you would in grade 9 geometry, find the slope, then use y = mx + b to find the equation.
algebra - Kanon, Wednesday, November 18, 2009 at 10:21pm
Did you try to answer yourself ?
x = number of lessons
y = number of vocabulary words
I help you : 5x = 20y ( 5th French lesson, you have learned 20 vocabulary words )
Good luck :)
Kanon, that is wrong. algebra - Reiny, Wednesday, November 18, 2009 at 10:54pm
slope = (40-20)/(10-5) = 4
so y = mx + b becomes
y = 4x + b
sub in (5,20)
20 = 4(5) + b
b = 0
so y = 4x is the equation.